# OpenVMS

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Computer operating system

Operating system

OpenVMS OpenVMS V7.3-1 running the CDE-based DECwindows "New Desktop" GUI Developer VMS Software Inc (VSI)[1] (previously Digital Equipment Corporation, Compaq, Hewlett-Packard) Written in Primarily C, BLISS, VAX MACRO, DCL.[2] Other languages also used.[3] Working state Current Source model Closed-source with open-source components. Formerly source available[4][5] Initial release Announced: October 25, 1977; 48 years ago (1977-10-25) V1.0 / August 1978; 47 years ago (1978-08) Latest release V9.2-3 / November 20, 2024; 19 months ago (2024-11-20) Marketing target Servers (historically Minicomputers, Workstations) Available in English, Japanese.[6] Historical support for Chinese (both Traditional and Simplified characters), Korean, Thai.[7] Update method Concurrent upgrades, rolling upgrades Package manager PCSI and VMSINSTAL Supported platforms VAX, Alpha, Itanium, x86-64 Kernel type Monolithic kernel with loadable modules Influenced VAXELN, MICA, Windows NT Influenced by RSX-11M Default user interface DCL CLI and DECwindows GUI License Proprietary Official website vmssoftware.com

**OpenVMS**, often referred to as just **VMS**,[8] is a [multi-user](/source/Multi-user), [multiprocessing](/source/Multiprocessing) and [virtual memory](/source/Virtual_memory)-based [operating system](/source/Operating_system). It is designed to support [time-sharing](/source/Time-sharing), [batch processing](/source/Batch_processing), [transaction processing](/source/Transaction_processing) and [workstation](/source/Workstation) applications.[9] Customers using OpenVMS include banks and financial services, hospitals and healthcare, telecommunications operators, network information services, and industrial manufacturers.[10][11] During the 1990s and 2000s, there were approximately half a million VMS systems in operation worldwide.[12][13][14]

It was first announced by [Digital Equipment Corporation](/source/Digital_Equipment_Corporation) (DEC) as **VAX/VMS** (*Virtual Address eXtension/Virtual Memory System*[15]) alongside the [VAX-11/780](/source/VAX-11%2F780) minicomputer in 1977.[16][17][18] OpenVMS has subsequently been [ported](/source/Ported) to run on [DEC Alpha](/source/DEC_Alpha) systems, the [Itanium](/source/Itanium)-based [HPE Integrity Servers](/source/HPE_Integrity_Servers),[19] and select [x86-64](/source/X86-64) hardware and [hypervisors](/source/Hypervisor).[20] Since 2014, OpenVMS is developed and supported by VMS Software Inc. (VSI).[21][22] OpenVMS offers [high availability](/source/High_availability) through [clustering](/source/Computer_cluster)—the ability to distribute the system over multiple physical machines.[23] This allows clustered applications and data to remain continuously available while operating system software and hardware maintenance and upgrades are performed,[24] or if part of the cluster is destroyed.[25] VMS cluster uptimes of 17 years have been reported.[26]

## History

### Origin and name changes

Stylized "VAX/VMS" used by Digital

In April 1975, [Digital Equipment Corporation](/source/Digital_Equipment_Corporation) (DEC) embarked on a project to design a [32-bit](/source/32-bit) extension to its [PDP-11](/source/PDP-11) computer line. The hardware component was code named *Star*; the operating system was code named *Starlet*. Roger Gourd was the project lead for VMS. Software engineers [Dave Cutler](/source/Dave_Cutler), [Dick Hustvedt](/source/Dick_Hustvedt), and Peter Lipman acted as technical project leaders.[27] To avoid a repetition of PDP-11's many incompatible operating systems, the new operating system would be capable of [real-time](/source/Real-time_operating_system), [time-sharing](/source/Time-sharing), and [transaction processing](/source/Transaction_processing).[28] The Star and Starlet projects culminated in the [VAX-11/780](/source/VAX-11#VAX-11/780) computer and the VAX/VMS operating system. The Starlet project's code name survives in VMS in the name of several of the system libraries, including STARLET.OLB and STARLET.MLB.[29] VMS was mostly written in [VAX MACRO](/source/VAX_MACRO) with some components written in [BLISS](/source/BLISS).[8]

One of the original goals for VMS was [backward compatibility](/source/Backward_compatibility) with DEC's existing [RSX-11M](/source/RSX-11M) operating system.[8] Prior to the V4.0 release, VAX/VMS included a compatibility layer named the *RSX Application Migration Executive* (RSX AME), which allowed user-mode RSX-11M software to be run unmodified on top of VMS.[30] The RSX AME played an important role on early versions of VAX/VMS, which used certain RSX-11M user-mode utilities before native VAX versions had been developed.[8] By the V3.0 release, all compatibility-mode utilities were replaced with native implementations.[31] In VAX/VMS V4.0, RSX AME was removed from the base system, and replaced with an optional layered product named *VAX-11 RSX*.[32]

"Albert the [Cheshire Cat](/source/Cheshire_Cat)" mascot for VAX/VMS, used by the [DECUS](/source/DECUS) VAX SIG[33][34]

By the early 1980s VAX/VMS was very successful in the market. Although created on [Unix](/source/Unix) on DEC systems, [Ingres](/source/Ingres_(database)) ported to VMS believing that doing so was necessary for commercial success. Demand for the VMS version was so much greater that the company neglected the Unix version.[35] A number of distributions of VAX/VMS were created:

- **MicroVMS** was a distribution of VAX/VMS designed for [MicroVAX](/source/MicroVAX) and [VAXstation](/source/VAXstation) hardware, which had less memory and disk space than larger VAX systems of the time.[36] MicroVMS split up VAX/VMS into multiple kits, which a customer could use to install a subset of VAX/VMS tailored to their specific requirements.[37] MicroVMS releases were produced for each of the V4.x releases of VAX/VMS and was discontinued when VAX/VMS V5.0 was released.[38][39]

- **Desktop-VMS** was a short-lived distribution of VAX/VMS sold with [VAXstation](/source/VAXstation) systems. It consisted of a single [CD-ROM](/source/CD-ROM) containing a bundle of VMS, DECwindows, DECnet, VAXcluster support, and a setup process designed for non-technical users.[40][41] Desktop-VMS could either be run directly from the CD or could be installed onto a hard drive.[42] Desktop-VMS had its own versioning scheme beginning with V1.0, which corresponded to the V5.x releases of VMS.[43]

- An unofficial derivative of VAX/VMS named **MOS VP** ([Russian](/source/Russian_language): Многофункциональная операционная система с виртуальной памятью, МОС ВП, [lit.](/source/Literal_translation) 'Multifunctional Operating System with Virtual Memory')[44] was created in the [Soviet Union](/source/Soviet_Union) during the 1980s for the [SM 1700](/source/VAX#Clones) line of VAX clone hardware.[45][46] MOS VP added support for the [Cyrillic script](/source/Cyrillic_script) and translated parts of the user interface into Russian.[47] Similar derivatives of MicroVMS known as *MicroMOS VP* ([Russian](/source/Russian_language): МикроМОС ВП) or *MOS-32M* ([Russian](/source/Russian_language): МОС-32М) were also created.

With the V5.0 release in April 1988, DEC began to refer to VAX/VMS as simply VMS in its documentation.[48] In July 1992,[49] DEC renamed VAX/VMS to OpenVMS as an indication of its support of [open systems](/source/Open_system_(computing)) industry standards such as [POSIX](/source/POSIX) and Unix compatibility,[50] and to drop the VAX connection since a migration to a different architecture was underway. The OpenVMS name was first used with the OpenVMS AXP V1.0 release in November 1992. DEC began using the OpenVMS VAX name with the V6.0 release in June 1993.[51]

### Port to Alpha

See also: [DEC PRISM § Legacy](/source/DEC_PRISM#Legacy), and [DEC Alpha § History](/source/DEC_Alpha#History)

"Vernon the Shark" logo for OpenVMS[52]

During the 1980s, DEC planned to replace the VAX platform and the VMS operating system with the [PRISM](/source/DEC_PRISM) architecture and the [MICA](/source/DEC_MICA) operating system.[53] When these projects were cancelled in 1988, a team was set up to design new VAX/VMS systems of comparable performance to [RISC](/source/RISC)-based Unix systems.[54] After a number of failed attempts to design a faster VAX-compatible processor, the group demonstrated the feasibility of [porting](/source/Porting) VMS and its applications to a RISC architecture based on PRISM.[55] This led to the creation of the [Alpha](/source/DEC_Alpha) architecture.[56] The project to port VMS to Alpha began in 1989, and first booted on a prototype [Alpha EV3](/source/Alpha_21064#History)-based *Alpha Demonstration Unit* in early 1991.[55][57]

The main challenge in porting VMS to a new architecture was that VMS and the VAX were designed together, meaning that VMS was dependent on certain details of the VAX architecture.[58] Furthermore, a significant amount of the VMS kernel, layered products, and customer-developed applications were implemented in [VAX MACRO](/source/VAX_MACRO) assembly code.[8] Some of the changes needed to decouple VMS from the VAX architecture included the creation of the *MACRO-32* compiler, which treated VAX MACRO as a [high-level language](/source/High-level_language), and compiled it to Alpha [object code](/source/Object_code),[59] and the emulation of certain low-level details of the VAX architecture in [PALcode](/source/PALcode), such as [interrupt handling](/source/Interrupt_handling) and atomic queue instructions.

The VMS port to Alpha resulted in the creation of two separate codebases: one for [VAX](/source/VAX), and another for Alpha.[4] The Alpha code library was based on a snapshot of the VAX/VMS code base circa V5.4-2.[60] 1992 saw the release of the first version of OpenVMS for [Alpha AXP](/source/Alpha_AXP) systems, designated *OpenVMS AXP V1.0*. In 1994, with the release of OpenVMS V6.1, feature (and version number) parity between the VAX and Alpha variants was achieved; this was the so-called Functional Equivalence release.[60] The decision to use the 1.x version numbering stream for the pre-production quality releases of OpenVMS AXP confused some customers, and was not repeated in the subsequent ports of OpenVMS to new platforms.[58]

When VMS was ported to Alpha, it was initially left as a 32-bit only operating system.[59] This was done to ensure backwards compatibility with software written for the 32-bit VAX. 64-bit addressing was first added for Alpha in the V7.0 release.[61] In order to allow 64-bit code to interoperate with older 32-bit code, OpenVMS does not create a distinction between 32-bit and 64-bit executables, but instead allows for both 32-bit and 64-bit pointers to be used within the same code.[62] This is known as mixed pointer support. The 64-bit OpenVMS Alpha releases support a maximum virtual address space size of 8TiB (a 43-bit address space), which is the maximum supported by the [Alpha 21064](/source/Alpha_21064) and [Alpha 21164](/source/Alpha_21164).[63]

One of the more noteworthy Alpha-only features of OpenVMS was *OpenVMS Galaxy*, which allowed the [partitioning](/source/Logical_partition) of a single SMP server to run multiple instances of OpenVMS. Galaxy supported dynamic resource allocation to running partitions, and the ability to share memory between partitions.[64][65]

### Port to Intel Itanium

"Swoosh" logo used by HP for OpenVMS

In 2001, prior to its acquisition by [Hewlett-Packard](/source/Hewlett-Packard), [Compaq](/source/Compaq) announced the port of OpenVMS to the [Intel](/source/Intel) [Itanium](/source/Itanium) architecture.[66] The Itanium port was the result of Compaq's decision to discontinue future development of the Alpha architecture in favour of adopting the then-new Itanium architecture.[67] The porting began in late 2001, and the first boot on took place on January 31, 2003.[68] The first boot consisted of booting a minimal system configuration on a [HP i2000](/source/List_of_Hewlett-Packard_products#Itanium_based) workstation, logging in as the SYSTEM user, and running the DIRECTORY command. The Itanium port of OpenVMS supports specific models and configurations of [HPE Integrity Servers](/source/HPE_Integrity_Servers).[9] The Itanium releases were originally named *HP OpenVMS Industry Standard 64 for Integrity Servers*, although the names *OpenVMS I64* or *OpenVMS for Integrity Servers* are more commonly used.[69]

The Itanium port was accomplished using source code maintained in common within the OpenVMS Alpha source code library, with the addition of conditional code and additional modules where changes specific to Itanium were required.[58] This required certain architectural dependencies of OpenVMS to be replaced, or emulated in software. Some of the changes included using the [Extensible Firmware Interface](/source/Extensible_Firmware_Interface) (EFI) to boot the operating system,[70] reimplementing the functionality previously provided by Alpha PALcode inside the kernel,[71] using new executable file formats ([Executable and Linkable Format](/source/Executable_and_Linkable_Format) and [DWARF](/source/DWARF)),[72] and adopting [IEEE 754](/source/IEEE_754) as the default floating point format.[73]

As with the VAX to Alpha port, a binary translator for Alpha to Itanium was made available, allowing user-mode OpenVMS Alpha software to be ported to Itanium in situations where it was not possible to recompile the source code. This translator is known as the *Alpha Environment Software Translator* (AEST), and it also supported translating VAX executables which had already been translated with VEST.[74]

Two pre-production releases, OpenVMS I64 V8.0 and V8.1, were available on June 30, 2003, and on December 18, 2003. These releases were intended for HP organizations and third-party vendors involved with porting software packages to OpenVMS I64. The first production release, V8.2, was released in February 2005. V8.2 was also released for Alpha; subsequent V8.x releases of OpenVMS have maintained feature parity between the Alpha and Itanium architectures.[75]

### Port to x86-64

When VMS Software Inc. (VSI) announced that they had secured the rights to develop the OpenVMS operating system from HP, they also announced their intention to port OpenVMS to the [x86-64](/source/X86-64) architecture.[76] The porting effort ran concurrently with the establishment of the company, as well as the development of VSI's own Itanium and Alpha releases of OpenVMS V8.4-x.

The x86-64 port is targeted for specific servers from [HPE](/source/Hewlett_Packard_Enterprise) and [Dell](/source/Dell), as well as certain virtual machine [hypervisors](/source/Hypervisor).[77] Initial support was targeted for [KVM](/source/Kernel-based_Virtual_Machine) and [VirtualBox](/source/VirtualBox). Support for [VMware](/source/VMware) was announced in 2020, and [Hyper-V](/source/Hyper-V) is being explored as a future target.[78] In 2021, the x86-64 port was demonstrated running on an [Intel Atom](/source/Intel_Atom)-based [single-board computer](/source/Single-board_computer).[79]

As with the Alpha and Itanium ports, the x86-64 port made some changes to simplify porting and supporting OpenVMS on the new platform including: replacing the proprietary GEM compiler backend used by the VMS compilers with [LLVM](/source/LLVM),[80] changing the boot process so that OpenVMS is booted from a memory disk,[81] and simulating the four privilege levels of OpenVMS in software since only two of x86-64's privilege levels are usable by OpenVMS.[71]

The first boot was announced on May 14, 2019. This involved booting OpenVMS on VirtualBox, and successfully running the [DIRECTORY](/source/Directory_(OpenVMS_command)) command.[82] In May 2020, the V9.0 Early Adopter's Kit release was made available to a small number of customers. This consisted of the OpenVMS operating system running in a VirtualBox VM with certain limitations; most significantly, few layered products were available, and code can only be compiled for x86-64 using cross compilers which run on Itanium-based OpenVMS systems.[20] Following the V9.0 release, VSI released a series of updates on a monthly or bimonthly basis which added additional functionality and hypervisor support. These were designated V9.0-A through V9.0-H.[83] In June 2021, VSI released the V9.1 Field Test, making it available to VSI's customers and partners.[84] V9.1 shipped as an [ISO image](/source/ISO_image) which can be installed onto a variety of hypervisors, and onto [HPE ProLiant DL380](/source/ProLiant) servers starting with the V9.1-A release.[85]

### Influence

During the 1980s, the MICA operating system for the PRISM architecture was intended to be the eventual successor to VMS. MICA was designed to maintain backwards compatibility with VMS applications while also supporting [Ultrix](/source/Ultrix) applications on top of the same kernel.[86] MICA was ultimately cancelled along with the rest of the PRISM platform, leading Dave Cutler to leave DEC for Microsoft. At Microsoft, Cutler led the creation of the [Windows NT](/source/Windows_NT) operating system, which was heavily inspired by the architecture of MICA.[87] As a result, VMS is considered an ancestor of [Windows NT](/source/Windows_NT), together with [RSX-11](/source/RSX-11), [VAXELN](/source/VAXELN) and MICA, and many similarities exist between VMS and NT.[88]

A now-defunct project named *FreeVMS* attempted to develop an [open-source](/source/Open-source_software) operating system following VMS conventions.[89][90] FreeVMS was built on top of the [L4 microkernel](/source/L4_microkernel_family) and supported the [x86-64](/source/X86-64) architecture. Prior work investigating the implementation of VMS using a microkernel-based architecture had previously been undertaken as a prototyping exercise by DEC employees with assistance from [Carnegie Mellon University](/source/Carnegie_Mellon_University) using the [Mach 3.0](/source/Mach_(kernel)) microkernel ported to [VAXstation 3100](/source/VAXstation#VAXstation_3100_Series) hardware, adopting a multiserver architectural model.[91]

## Architecture

The architecture of the OpenVMS operating system, demonstrating the layers of the system, and the access modes in which they typically run

The OpenVMS operating system has a layered architecture, consisting of a privileged *Executive*, an intermediately privileged Command Language Interpreter, and unprivileged utilities and [run-time libraries](/source/Runtime_library) (RTLs).[92] Unprivileged code typically invokes the functionality of the Executive through *system services* (equivalent to [system calls](/source/System_call) in other operating systems).

OpenVMS' layers and mechanisms are built around certain features of the VAX architecture, including:[92][93]

- The availability of four [processor access modes](/source/Protection_ring) (named *Kernel*, *Executive*, *Supervisor* and *User*, in order of decreasing privilege). Each mode has its own stack, and each [memory page](/source/Memory_page) can have [memory protections](/source/Memory_protection) specified per-mode.

- A [virtual address space](/source/Virtual_address_space) which is partitioned between process-private space sections, and system space sections which are common to all processes.

- 32 [interrupt priority levels](/source/Interrupt_priority_level) which are used for [synchronization](/source/Synchronization_(computer_science)).

- Hardware support for delivering [asynchronous system traps](/source/Asynchronous_system_trap) to processes.

These VAX architecture mechanisms are implemented on Alpha, Itanium and x86-64 by either mapping to corresponding hardware mechanisms on those architectures, or through emulation (via [PALcode](/source/PALcode) on Alpha, or in software on Itanium and x86-64).[71]

### Executive and Kernel

The OpenVMS Executive comprises the privileged code and data structures which reside in the system space. The Executive is further subdivided between the *Kernel*, which consists of the code which runs at the kernel access mode, and the less-privileged code outside of the Kernel which runs at the executive access mode.[92]

The components of the Executive which run at executive access mode include the [Record Management Services](/source/Record_Management_Services), and certain system services such as image activation. The main distinction between the kernel and executive access modes is that most of the operating system's core data structures can be read from executive mode, but require kernel mode to be written to.[93] Code running at executive mode can switch to kernel mode at will, meaning that the barrier between the kernel and executive modes is intended as a safeguard against accidental corruption as opposed to a security mechanism.[94]

The [Kernel](/source/Kernel_(operating_system)) comprises the operating system's core data structures (e.g. page tables, the I/O database and scheduling data), and the routines which operate on these structures. The Kernel is typically described as having three major subsystems: I/O, Process and Time Management, Memory Management.[92][93] In addition, other functionality such as [logical name](/source/Files-11#Logical_names) management, synchronization and system service dispatch are implemented inside the Kernel.

OpenVMS allows user-mode code with suitable privileges to switch to executive or kernel mode using the $CMEXEC and $CMKRNL system services, respectively.[95] This allows code outside of system space to have direct access to the Executive's routines and system services. In addition to allowing third-party extensions to the operating system, Privileged Images are used by core operating system utilities to manipulate operating system data structures through undocumented interfaces.[96]

### File system

Main articles: [Files-11](/source/Files-11) and [Record Management Services](/source/Record_Management_Services)

The typical user and application interface into the [file system](/source/File_system) is the [Record Management Services](/source/Record_Management_Services) (RMS), although applications can interface directly with the underlying file system through the [QIO](/source/QIO) system services.[97] The file systems supported by VMS are referred to as the [Files-11](/source/Files-11) *On-Disk Structures* (ODS), the most significant of which are *ODS-2* and *ODS-5*.[98] VMS is also capable of accessing files on [ISO 9660](/source/ISO_9660) [CD-ROMs](/source/CD-ROM) and [magnetic tape](/source/Magnetic_tape) with [ANSI tape labels](/source/Tape_labels#ANSI_tape_labels).[99]

Files-11 is limited to 2 TiB volumes.[98] DEC attempted to replace it with a [log-structured file system](/source/Log-structured_file_system) named Spiralog, first released in 1995.[100] However, Spiralog was discontinued due to a variety of problems, including issues with handling full volumes.[100] Instead, there has been discussion of porting the open-source GFS2 file system to OpenVMS.[101]

### Command Language Interpreter

An OpenVMS Command Language Interpreter (CLI) implements a [command-line interface](/source/Command-line_interface) for OpenVMS, responsible for executing individual commands and *command procedures* (equivalent to [shell scripts](/source/Shell_script) or [batch files](/source/Batch_file)).[102] The standard CLI for OpenVMS is the [DIGITAL Command Language](/source/DIGITAL_Command_Language), although other options are available.

Unlike [Unix shells](/source/Unix_shell), which typically run in their own isolated process and behave like any other user-mode program, OpenVMS CLIs are an optional component of a process, which exist alongside any executable image which that process may run.[103] Whereas a Unix shell will typically run executables by creating a separate process using [fork-exec](/source/Fork-exec), an OpenVMS CLI will typically load the executable image into the same process, transfer control to the image, and ensure that control is transferred back to CLI once the image has exited and that the process is returned to its original state.[92]

Because the CLI is loaded into the same address space as user code, and the CLI is responsible for invoking image activation and image rundown, the CLI is mapped into the process address space at supervisor access mode, a higher level of privilege than most user code. This is in order to prevent accidental or malicious manipulation of the CLI's code and data structures by user-mode code.[92][103]

## Features

VAXstation 4000 model 96 running OpenVMS V6.1, DECwindows Motif and the [NCSA Mosaic](/source/NCSA_Mosaic) browser

### Clustering

Main article: [VMScluster](/source/VMScluster)

OpenVMS supports [clustering](/source/Computer_cluster) (first called *VAXcluster* and later *VMScluster*), where multiple computers run their own instance of the operating system. Clustered computers (nodes) may be fully independent from each other, or they may share devices like disk drives and printers. Communication across nodes provides a [single system image](/source/Single_system_image) abstraction.[104] Nodes may be connected to each other via a proprietary hardware connection called Cluster Interconnect or via a standard [Ethernet](/source/Ethernet) [LAN](/source/Local_area_network).

OpenVMS supports up to 96 nodes in a single cluster. It also allows mixed-architecture clusters.[23] OpenVMS clusters allow applications to function during planned or unplanned outages.[105] Planned outages include hardware and software upgrades.[24]

### Networking

Main article: [DECnet](/source/DECnet)

The [DECnet](/source/DECnet) protocol suite is tightly integrated into VMS, allowing remote logins, as well as transparent access to files, printers and other resources on VMS systems over a network.[106] VAX/VMS V1.0 featured support for DECnet Phase II,[107] and modern versions of VMS support both the traditional Phase IV DECnet protocol, as well as the [OSI-compatible](/source/OSI_protocols) Phase V (also known as *DECnet-Plus*).[108] Support for [TCP/IP](/source/TCP%2FIP) is provided by the optional *TCP/IP Services for OpenVMS* layered product (originally known as the *VMS/ULTRIX Connection*, then as the *[ULTRIX](/source/ULTRIX) Communications Extensions* or UCX).[109][110] TCP/IP Services is based on a port of the [BSD](/source/Berkeley_Software_Distribution) network stack to OpenVMS,[111] along with support for common protocols such as [SSH](/source/SSH), [DHCP](/source/DHCP), [FTP](/source/FTP) and [SMTP](/source/SMTP).

DEC sold a software package named [PATHWORKS](/source/PATHWORKS) (originally known as the *Personal Computer Systems Architecture* or PCSA) which allowed [personal computers](/source/Personal_computer) running [MS-DOS](/source/MS-DOS), [Microsoft Windows](/source/Microsoft_Windows) or [OS/2](/source/OS%2F2), or the [Apple Macintosh](/source/Apple_Macintosh) to serve as a terminal for VMS systems, or to use VMS systems as a file or print server.[112] PATHWORKS was later renamed to *Advanced Server for OpenVMS*, and was eventually replaced with a VMS port of [Samba](/source/Samba_(software)) at the time of the Itanium port.[113]

DEC provided the [Local Area Transport](/source/Local_Area_Transport) (LAT) protocol which allowed remote terminals and printers to be attached to a VMS system through a [terminal server](/source/Terminal_server) such as one of the [DECserver](/source/DECserver) family.[114]

### Programming

DEC (and its successor companies) provided a wide variety of programming languages for VMS. Officially supported languages on VMS, either current or historical, include:[115][116][117]

- [VAX MACRO](/source/VAX_MACRO)

- [BLISS](/source/BLISS)

- [C](/source/C_(programming_language))

- [DCL](/source/DIGITAL_Command_Language)

- [Fortran](/source/Fortran)

- [Pascal](/source/Pascal_(programming_language))

- [COBOL](/source/COBOL)

- [BASIC](/source/BASIC)

- [C++](/source/C%2B%2B)

- [Java](/source/Java_(programming_language))

- [Common Lisp](/source/Common_Lisp)

- [APL](/source/APL_(programming_language))

- [Ada](/source/Ada_(programming_language))

- [PL/I](/source/PL%2FI)

- [DIBOL](/source/DIBOL)

- [CORAL](/source/CORAL)

- [OPS5](/source/OPS5)

- [RPG II](/source/IBM_RPG_II)

- [MUMPS](/source/MUMPS)

- [MACRO-11](/source/MACRO-11)

- [DECTPU](/source/DEC_Text_Processing_Utility)

- [Lua](/source/Lua_(programming_language))

- VAX SCAN

Among OpenVMS's notable features is the *Common Language Environment*, a strictly defined standard that specifies calling conventions for functions and routines, including use of [stacks](/source/Stack_(abstract_data_type)), [registers](/source/Processor_register), etc., independent of programming language.[118] Because of this, it is possible to call a routine written in one language (for example, Fortran) from another (for example, COBOL), without needing to know the implementation details of the target language. OpenVMS itself is implemented in a variety of different languages and the common language environment and calling standard supports freely mixing these languages.[119] DEC created a tool named the *Structure Definition Language* (SDL), which allowed [data type](/source/Data_type) definitions to be generated for different languages from a common definition.[120]

The set of languages available directly with the operating system is restricted to C, Fortran, Pascal, BASIC, C++, BLISS and COBOL. Freely available open source languages include Lua, PHP, Python, Scala and Java.[121]

#### Development tools

The "Grey Wall" of VAX/VMS documentation, at [Living Computers: Museum + Labs](/source/Living_Computers%3A_Museum_%2B_Labs)

DEC provided a collection of software development tools in a layered product named *DECset* (originally named *VAXset*).[115] This consisted of the following tools:[122]

- [Language-Sensitive Editor](/source/Language-Sensitive_Editor) (LSE)

- *Code Management System* (CMS) a [version control](/source/Version_control) system

- *Module Management System* (MMS), a [build tool](/source/Build_automation)

- the *Source Code Analyzer (*SCA), a [static analyzer](/source/Static_analyzer)

- the *Performance and Coverage Analyzer* (*PCA*), a [profiler](/source/Profiling_(computer_programming))

- *Digital Test Manager* (DTM), as a test manager

- In addition, a number of [text editors](/source/Text_editor) are included in the operating system, including [EDT](/source/EDT_(Digital)), [EVE](/source/EVE_(text_editor)) and [TECO](/source/TECO_(text_editor)).[123]

The OpenVMS Debugger supports all DEC compilers and many third-party languages. It allows breakpoints, watchpoints and interactive runtime program debugging using either a [command line](/source/Command_line_interface) or [graphical user interface](/source/Graphical_user_interface).[124] A pair of lower-level debuggers, named *DELTA* and *XDELTA*, can be used to debug privileged code in additional to normal application code.[125]

In 2019, VSI released an officially supported [Integrated Development Environment](/source/Integrated_Development_Environment) for VMS based on [Visual Studio Code](/source/Visual_Studio_Code).[77] This allows VMS applications to be developed and debugged remotely from a [Microsoft Windows](/source/Microsoft_Windows), [macOS](/source/MacOS) or [Linux](/source/Linux) workstation.[126]

#### Database management

DEC created a number of optional [database](/source/Database) products for VMS, some of which were marketed as the *VAX Information Architecture* family.[127] These products included:

- [Rdb](/source/Oracle_Rdb) – A [relational database](/source/Relational_database) system which originally used the proprietary *Relational Data Operator* (RDO) query interface, but later gained [SQL](/source/SQL) support.[128]

- *DBMS* – A database management system which uses the [CODASYL](/source/CODASYL) [network model](/source/Network_model) and *Data Manipulation Language* (DML).

- [Digital Standard MUMPS](/source/Digital_Standard_MUMPS) (DSM) – an integrated programming language and [key-value database](/source/Key-value_database).[115]

- *Common Data Dictionary* (CDD) – a central [database schema](/source/Database_schema) repository, which allowed schemas to be shared between different applications, and data definitions to be generated for different programming languages.

- [DATATRIEVE](/source/DATATRIEVE) – a query and reporting tool which could access data from RMS files as well as Rdb and DBMS databases.

- Application Control Management System (ACMS) – A [transaction processing monitor](/source/Transaction_processing_monitor), which allows applications to be created using a high-level *Task Description Language* (TDL). Individual steps of a transaction can be implemented using DCL commands, or Common Language Environment procedures. User interfaces can be implemented using TDMS, DECforms or Digital's [ALL-IN-1](/source/ALL-IN-1) office automation product.[129]

- *RALLY*, *DECadmire* – [Fourth-generation programming languages](/source/Fourth-generation_programming_language) (4GLs) for generating database-backed applications.[130] DECadmire featured integration with ACMS, and later provided support for generating [Visual Basic](/source/Visual_Basic) [client-server](/source/Client-server) applications for Windows PCs.[131]

In 1994, DEC sold Rdb, DBMS and CDD to [Oracle](/source/Oracle_Corporation), where they remain under active development.[132] In 1995, DEC sold DSM to [InterSystems](/source/InterSystems), who renamed it *Open M*, and eventually replaced it with their [Caché](/source/InterSystems_Cach%C3%A9) product.[133]

Examples of third-party database management systems for OpenVMS include [MariaDB](/source/MariaDB),[134] [Mimer SQL](/source/Mimer_SQL)[135] ([Itanium](/source/Itanium) and [x86-64](/source/X86-64)[136]), and [System 1032](/source/System_1032).[137]

### User interfaces

OpenVMS Alpha V8.4-2L1, showing the DCL CLI in a terminal session

VMS was originally designed to be used and managed interactively using DEC's text-based [video terminals](/source/Video_terminal) such as the [VT100](/source/VT100), or hardcopy terminals such as the [DECwriter](/source/DECwriter) series. Since the introduction of the [VAXstation](/source/VAXstation) line in 1984, VMS has optionally supported graphical user interfaces for use with workstations or [X terminals](/source/X_terminal) such as the [VT1000](/source/VT1000) series.

#### Text-based user interfaces

Main article: [DIGITAL Command Language](/source/DIGITAL_Command_Language)

The [DIGITAL Command Language](/source/DIGITAL_Command_Language) (DCL) has served as the primary [command language](/source/Command_language) interpreter (CLI) of OpenVMS since the first release.[138][30][9] Other official CLIs available for VMS include the [RSX-11](/source/RSX-11) Monitor Console Routine (MCR) (VAX only), and various [Unix shells](/source/Unix_shell).[115] DEC provided tools for creating [text-based user interface](/source/Text-based_user_interface) applications – the *Form Management System* (FMS) and *Terminal Data Management System* (TDMS), later succeeded by *DECforms*.[139][140][141] A lower level interface named *Screen Management Services* (SMG$), comparable to Unix [curses](/source/Curses_(programming_library)), also exists.[142]

#### Graphical user interfaces

VWS 4.5 running on top of VAX/VMS V5.5-2

DECwindows XUI window manager running on top of VAX/VMS V5.5-2

Over the years, VMS has gone through a number of different GUI toolkits and interfaces:

- The original graphical user interface for VMS was a proprietary [windowing system](/source/Windowing_system) known as the *VMS Workstation Software* (VWS), which was first released for the [VAXstation I](/source/VAXstation#VAXstation_I) in 1984.[143] It exposed an API called the User Interface Services (UIS).[144] It ran on a limited selection of VAX hardware.[145]

- In 1989, DEC replaced VWS with a new [X11](/source/X11)-based windowing system named *DECwindows*.[146] It was first included in VAX/VMS V5.1.[147] Early versions of DECwindows featured an interface built on top of a proprietary toolkit named the *X User Interface* (XUI). A layered product named UISX was provided to allow VWS/UIS applications to run on top of DECwindows.[148] Parts of XUI were subsequently used by the [Open Software Foundation](/source/Open_Software_Foundation) as the foundation of the [Motif toolkit](/source/Motif_toolkit).[149]

- In 1991, DEC replaced XUI with the Motif toolkit, creating *DECwindows Motif*.[150][151] As a result, the [Motif Window Manager](/source/Motif_Window_Manager) became the default DECwindows interface in OpenVMS V6.0,[147] although the XUI window manager remained as an option.

- In 1996, as part of OpenVMS V7.1,[147] DEC released the *New Desktop* interface for DECwindows Motif, based on the [Common Desktop Environment](/source/Common_Desktop_Environment) (CDE).[152] On Alpha and Itanium systems, it is still possible to select the older MWM-based UI (referred to as the "DECwindows Desktop") at login time. The New Desktop was never ported to the VAX releases of OpenVMS.

Versions of VMS running on DEC Alpha workstations in the 1990s supported [OpenGL](/source/OpenGL)[153] and [Accelerated Graphics Port](/source/Accelerated_Graphics_Port) (AGP) graphics adapters. VMS also provides support for older graphics standards such as [GKS](/source/Graphical_Kernel_System) and [PHIGS](/source/PHIGS).[154][155] Modern versions of DECwindows are based on [X.Org Server](/source/X.Org_Server).[9]

### Security

OpenVMS provides various security features and mechanisms, including security identifiers, resource identifiers, subsystem identifiers, [ACLs](/source/Access_control_list), [intrusion detection](/source/Intrusion_detection) and detailed security auditing and alarms.[156] Specific versions evaluated at [Trusted Computer System Evaluation Criteria](/source/Trusted_Computer_System_Evaluation_Criteria) Class C2 and, with the SEVMS security enhanced release at Class B1.[157] OpenVMS also holds an ITSEC E3 rating (see [NCSC](/source/National_Computer_Security_Center) and [Common Criteria](/source/Common_Criteria)).[158] Passwords are hashed using the [Purdy Polynomial](/source/George_B._Purdy#The_Purdy_polynomial).

#### Vulnerabilities

- Early versions of VMS included a number of privileged user accounts (including SYSTEM, FIELD, SYSTEST and DECNET) with default passwords which were often left unchanged by system managers.[159][160] A number of [computer worms](/source/Computer_worm) for VMS including the [WANK worm](/source/WANK_(computer_worm)) and the [Father Christmas worm](/source/Father_Christmas_(computer_worm)) exploited these default passwords to gain access to nodes on DECnet networks.[161] This issue was also described by [Clifford Stoll](/source/Clifford_Stoll) in *[The Cuckoo's Egg](/source/The_Cuckoo's_Egg_(book))* as a means by which [Markus Hess](/source/Markus_Hess) gained unauthorized access to VAX/VMS systems.[162] In V5.0, the default passwords were removed, and it became mandatory to provide passwords for these accounts during system setup.[39]

- A 33-year-old vulnerability in VMS on VAX and Alpha was discovered in 2017 and assigned the CVE ID [CVE](/source/CVE_(identifier))-[2017-17482](https://nvd.nist.gov/vuln/detail/CVE-2017-17482). On the affected platforms, this vulnerability allowed an attacker with access to the DCL command line to carry out a [privilege escalation](/source/Privilege_escalation) attack. The vulnerability relies on exploiting a [buffer overflow](/source/Buffer_overflow) bug in the DCL command processing code, the ability for a user to interrupt a running image (program [executable](/source/Executable)) with CTRL/Y and return to the DCL prompt, and the fact that DCL retains the privileges of the interrupted image.[163] The buffer overflow bug allowed [shellcode](/source/Shellcode) to be executed with the privileges of an interrupted image. This could be used in conjunction with an image installed with higher privileges than the attacker's account to bypass system security.[164]

### POSIX compatibility

Various official [Unix](/source/Unix) and [POSIX](/source/POSIX) compatibility layers were created for VMS. The first of these was *DEC/Shell*, which was a layered product consisting of ports of the [Bourne shell](/source/Bourne_shell) from [Version 7 Unix](/source/Version_7_Unix) and several other Unix utilities to VAX/VMS.[115] In 1992, DEC released the *POSIX for OpenVMS* layered product, which included a shell based on the [KornShell](/source/KornShell).[165] POSIX for OpenVMS was later replaced by the open-source *GNV* ([GNU](/source/GNU)'s not VMS) project, which was first included in OpenVMS media in 2002.[166] Amongst other GNU tools, GNV includes a port of the [Bash shell](/source/Bash_(Unix_shell)) to VMS.[167] Examples of third-party Unix compatibility layers for VMS include [Eunice](/source/Eunice_(software)).[168]

## Hobbyist programs

In 1997, OpenVMS and a number of layered products were made available free of charge for hobbyist, non-commercial use as part of the *OpenVMS Hobbyist Program*.[169] Since then, several companies producing OpenVMS software have made their products available under the same terms, such as Process Software.[170] Prior to the x86-64 port, the age and cost of hardware capable of running OpenVMS made [emulators](/source/Emulator) such as [SIMH](/source/SIMH) a common choice for hobbyist installations.[171]

In March 2020, HPE announced the end of the OpenVMS Hobbyist Program.[172] This was followed by VSI's announcement of the *Community License Program* (CLP) in April 2020, which was intended as a replacement for the HPE Hobbyist Program.[173] The CLP was launched in July 2020, and provides licenses for VSI OpenVMS releases on Alpha, Integrity and x86-64 systems.[174] OpenVMS for VAX is not covered by the CLP, since there are no VSI releases of OpenVMS VAX, and the old versions are still owned by HPE.[175]

## Release history

Release history of OpenVMS Vendor Version Release date [176][8][177] End of support [178][179][180] Platform Significant changes, new hardware support [181][147] DEC Unsupported: X0.5[n 1] April 1978[182] ? VAX First version shipped to customers[29] Unsupported: V1.0 August 1978 First production release Unsupported: V1.01 ?[n 2] Bug fixes[183] Unsupported: V1.5 February 1979[n 3] Support for native COBOL, BLISS compilers[183] Unsupported: V1.6 August 1979 RMS-11 updates[184] Unsupported: V2.0 April 1980 VAX-11/750, new utilities including EDT Unsupported: V2.1 ?[n 4] ? Unsupported: V2.2 April 1981 Process limit increased to 8,192[186] Unsupported: V2.3 May 1981[187] Security enhancements[188] Unsupported: V2.4 ? ? Unsupported: V2.5 ? BACKUP utility[189] Unsupported: V3.0 April 1982 VAX-11/730, VAX-11/725, VAX-11/782, ASMP Unsupported: V3.1 August 1982 PL/I runtime bundled with base OS[190] Unsupported: V3.2 December 1982 Support for RA60, RA80, RA81 disks[191] Unsupported: V3.3 April 1983 HSC50 disk controller, BACKUP changes[192] Unsupported: V3.4 June 1983 Ethernet support for DECnet,[193] VAX-11/785 Unsupported: V3.5 November 1983 Support for new I/O devices[194] Unsupported: V3.6 April 1984 Bug fixes[195] Unsupported: V3.7 August 1984 Support for new I/O devices[196] Unsupported: V4.0 September 1984 VAX 8600, MicroVMS, VAXclusters[197] Unsupported: V4.1 January 1985 MicroVAX/VAXstation I, II[198] Unsupported: V4.2 October 1985 Text Processing Utility Unsupported: V4.3 December 1985 DELUA Ethernet adapter support Unsupported: V4.3A January 1986 VAX 8200 Unsupported: V4.4 July 1986 VAX 8800/8700/85xx, Volume Shadowing Unsupported: V4.5 November 1986 Support for more memory in MicroVAX II Unsupported: V4.5A December 1986 Ethernet VAXclusters Unsupported: V4.5B March 1987 VAXstation/MicroVAX 2000 Unsupported: V4.5C May 1987 MicroVAX 2000 cluster support Unsupported: V4.6 August 1987 VAX 8250/8350/8530, RMS Journalling Unsupported: V4.7 January 1988 First release installable from CD-ROM Unsupported: V4.7A March 1988 VAXstation 3200/3500, MicroVAX 3500/3600 Unsupported: V5.0 April 1988 VAX 6000, SMP, LMF, Modular Executive Unsupported: V5.0-1 August 1988 Bug fixes Unsupported: V5.0-2 October 1988 Unsupported: V5.0-2A MicroVAX 3300/3400 Unsupported: V5.1 February 1989 DECwindows Unsupported: V5.1-B VAXstation 3100 30/40, Desktop-VMS Unsupported: V5.1-1 June 1989 VAXstation 3520/3540, MicroVAX 3800/3900 Unsupported: V5.2 September 1989 Cluster-wide process visibility/management Unsupported: V5.2-1 October 1989 VAXstation 3100 38/48 Unsupported: V5.3 January 1990 Support for third-party SCSI devices Unsupported: V5.3-1 April 1990 Support for VAXstation SPX graphics Unsupported: V5.3-2 May 1990 Support for new I/O devices Unsupported: V5.4 October 1990 VAX 65xx, VAX Vector Architecture Unsupported: V5.4-0A VAX 9000, bug fixes for VAX 6000 systems Unsupported: V5.4-1 November 1990 New models of VAX 9000, VAXstation, VAXft Unsupported: V5.4-1A January 1991 VAX 6000-400 Unsupported: V5.4-2 March 1991 VAX 4000 Model 200, new I/O devices Unsupported: V5.4-3 October 1991 FDDI adapter support Unsupported: V5.5 November 1991 Cluster-wide batch queue, new VAX models Unsupported: A5.5 Same as V5.5 but without new batch queue Unsupported: V5.5-1 July 1992 Bug fixes for batch/print queue Unsupported: V5.5-2HW September 1992 VAX 7000/10000, and other new VAX hardware Unsupported: V5.5-2 November 1992 September 1995 Consolidation of previous hardware releases Unsupported: V5.5-2H4 August 1993 New VAX 4000 models, additional I/O devices Unsupported: V5.5-2HF ? VAXft 810 Unsupported: V1.0[n 5] November 1992 Alpha First release for Alpha architecture Unsupported: V1.5 May 1993 Cluster and SMP support for Alpha Unsupported: V1.5-1H1 October 1993 New DEC 2000, DEC 3000 models Unsupported: V6.0 June 1993 VAX TCSEC C2 compliance, ISO 9660, Motif Unsupported: V6.1 April 1994 VAX, Alpha Merger of VAX and Alpha releases, PCSI Unsupported: V6.1-1H1 September 1994 Alpha New AlphaStation, AlphaServer models Unsupported: V6.1-1H2 November 1994 Unsupported: V6.2 June 1995 March 1998 VAX, Alpha Command Recall, DCL$PATH, SCSI clusters Unsupported: V6.2-1H1 December 1995 Alpha New AlphaStation, AlphaServer models Unsupported: V6.2-1H2 March 1996 Unsupported: V6.2-1H3 May 1996 Unsupported: V7.0 January 1996 VAX, Alpha 64-bit addressing, Fast I/O, Kernel Threads Unsupported: V7.1 January 1997 July 2000 Very Large Memory support, DCL PIPE, CDE Unsupported: V7.1-1H1 November 1997 Alpha AlphaServer 800 5/500, 1200 Unsupported: V7.1-1H2 April 1998 Support for booting from third-party devices Compaq Unsupported: V7.1-2 December 1998 Additional I/O device support Unsupported: V7.2 February 1999 June 2002 VAX, Alpha OpenVMS Galaxy, ODS-5, DCOM Unsupported: V7.2-1 July 1999 Alpha AlphaServer GS140, GS60, Tsunami Unsupported: V7.2-1H1 June 2000 AlphaServer GS160, GS320 Unsupported: V7.2-2 September 2001 December 2002 Minicopy support for Volume Shadowing Unsupported: V7.2-6C1 August 2001 ? DII COE conformance[199] Unsupported: V7.2-6C2 July 2002 Unsupported: V7.3 June 2001 December 2012 VAX Final release for VAX architecture June 2004 Alpha ATM and GBE clusters, Extended File Cache HP Unsupported: V7.3-1 August 2002 December 2004 Alpha Security and performance improvements Unsupported: V7.3-2 December 2003 December 2006 AlphaServer GS1280, DS15 Unsupported: V8.0 June 2003 December 2003 IA64 Evaluation release for Integrity servers Unsupported: V8.1 December 2003 February 2005 Second evaluation release for Integrity servers Unsupported: V8.2 February 2005 June 2010 Alpha, IA64 Production release for Integrity servers Unsupported: V8.2-1 September 2005 IA64 Support for HP Superdome, rx7620, rx8620 Unsupported: V8.3 August 2006 December 2015 Alpha, IA64 Support for additional Integrity server models Unsupported: V8.3-1H1 November 2007 IA64 Support for HP BL860c, dual-core Itanium Unsupported: V8.4 June 2010 December 2020 Alpha, IA64 Support for HPVM, clusters over TCP/IP[200] VSI Unsupported: V8.4-1H1 May 2015 December 2022 IA64 Support for Poulson processors[201] Unsupported: V8.4-2 March 2016 Support for HPE BL890c systems, UEFI 2.3 Unsupported: V8.4-2L1 September 2016 December 2024 OpenSSL updated to 1.0.2[202] Supported: V8.4-2L1 January 2017[203] December 2035 Alpha Supported: V8.4-2L2 July 2017 Final release for Alpha architecture[204] Supported: V8.4-2L3 April 2021 IA64 Final release for Integrity servers[204] Unsupported: V9.0 May 2020 June 2021 x86-64 x86-64 Early Adopter's Kit[205] Unsupported: V9.1 June 2021 September 2021 x86-64 Field Test[84] Unsupported: V9.1-A September 2021 April 2022 DECnet-Plus for x86-64[85] Unsupported: V9.2 July 2022 June 2023 x86-64 Limited Production Release[206] Unsupported: V9.2-1 June 2023 June 2025 AMD CPUs, OpenSSL 3.0, native compilers[207] Supported: V9.2-2 January 2024 December 2027 Bug fixes[208] Latest version: V9.2-3 November 2024 December 2028 VMware vMotion, VMDirectPath Future version: V9.2-4 June 2026 TBA iSCSI support Legend: Unsupported Supported Latest version Preview version Future version

1. **[^](#cite_ref-183)** X0.5 was also known as "Base Level 5".[182]

1. **[^](#cite_ref-185)** While an exact release date is unknown, the V1.01 change log dates in the release notes for V1.5 suggest it was released some time after November 1978.[183]

1. **[^](#cite_ref-186)** For some of the early VAX/VMS releases where an official release date is not known, the date of the Release Notes has been used an approximation.

1. **[^](#cite_ref-189)** The existence of releases V2.0 through V2.5 are documented in the V3.0 release notes.[185]

1. **[^](#cite_ref-203)** While the versioning scheme reset to V1.0 for the first AXP (Alpha) releases, these releases were contemporaneous with the V5.x releases and had a similar feature set.

## See also

- [Comparison of operating systems](/source/Comparison_of_operating_systems)

- [Terry Shannon](/source/Terry_Shannon_(writer))

## References

1. **[^](#cite_ref-VSI.CW2014_1-0)** Patrick Thibodeau (July 31, 2014). ["HP gives OpenVMS new life"](https://www.computerworld.com/article/2490683/operating-systems-hp-gives-openvms-new-life.html). *[Computerworld](/source/Computerworld)*. Retrieved October 21, 2021.

1. **[^](#cite_ref-2)** Camiel Vanderhoeven (May 30, 2021). ["How much of VMS is still in MACRO-32?"](https://groups.google.com/g/comp.os.vms/c/3SWQiRQA1Y4/m/npx29Nm-AwAJ). [Newsgroup](/source/Usenet_newsgroup): [comp.os.vms](news:comp.os.vms). Retrieved October 21, 2021.

1. **[^](#cite_ref-3)** ["2.7 In what language is OpenVMS written?"](https://web.archive.org/web/20180810010816/http://h41379.www4.hpe.com/faq/vmsfaq_002.html). *The OpenVMS Frequently Asked Questions (FAQ)*. [Hewlett Packard Enterprise](/source/Hewlett_Packard_Enterprise). Archived from [the original](http://h41379.www4.hpe.com/faq/vmsfaq_002.html#vms8) on August 10, 2018.

1. ^ [***a***](#cite_ref-wizard-vms-source_4-0) [***b***](#cite_ref-wizard-vms-source_4-1) ["Access to OpenVMS Source Code?"](https://web.archive.org/web/20171028043200/http://h41379.www4.hpe.com/wizard/wiz_2993.html). *HP OpenVMS Systems ask the wizard*. September 2, 1999. Archived from [the original](http://h41379.www4.hpe.com/wizard/wiz_2993.html) on October 28, 2017.

1. **[^](#cite_ref-5)** ["Webinar 16: x86 Update"](https://www.youtube.com/watch?v=E8X3tGlFgo8). VSI. October 15, 2021. [Archived](https://ghostarchive.org/varchive/youtube/20211211/E8X3tGlFgo8) from the original on December 11, 2021. Retrieved November 2, 2021.

1. **[^](#cite_ref-6)** ["Japanese OpenVMS OS (JVMS)"](https://web.archive.org/web/20240222074023/https://vmssoftware.com/products/jvms/). *VSI*. Archived from [the original](https://vmssoftware.com/products/jvms/) on February 22, 2024. Retrieved February 5, 2021.

1. **[^](#cite_ref-7)** Michael M. T. Yau (1993). ["Supporting the Chinese, Japanese, and Korean Languages in the OpenVMS Operating System"](http://www.dtjcd.vmsresource.org.uk/pdfs/dtj_v05-03_1993.pdf) (PDF). *Digital Technical Journal*. **5** (3): 63–79. Retrieved October 21, 2021.

1. ^ [***a***](#cite_ref-vms-20-years_8-0) [***b***](#cite_ref-vms-20-years_8-1) [***c***](#cite_ref-vms-20-years_8-2) [***d***](#cite_ref-vms-20-years_8-3) [***e***](#cite_ref-vms-20-years_8-4) [***f***](#cite_ref-vms-20-years_8-5) ["OpenVMS at 20 Nothing stops it"](https://h50146.www5.hpe.com/products/software/oe/openvms/history/vaxvms20/pdf/vmsbook.pdf) (PDF). Digital Equipment Corporation. October 1997. Retrieved February 12, 2021.

1. ^ [***a***](#cite_ref-vms-8.4-spd_9-0) [***b***](#cite_ref-vms-8.4-spd_9-1) [***c***](#cite_ref-vms-8.4-spd_9-2) [***d***](#cite_ref-vms-8.4-spd_9-3) ["Software Product Description and QuickSpecs - VSI OpenVMS Version 8.4-2L1 for Integrity servers"](https://vmssoftware.com/docs/VSI_OVMS_SPDQS_OS_V842L1I_UPD1.pdf) (PDF). VMS Software Inc. July 2019. Retrieved January 2, 2021.

1. **[^](#cite_ref-10)** ["VSI Business & New Products Update – April 9, 2019"](https://vmssoftware.com/docs/VMS_Software_Inc.-April_2019_Update_7am_Session.pdf) (PDF). VSI. April 2019. Retrieved May 4, 2021.

1. **[^](#cite_ref-11)** Charles Babcock (November 1, 2007). ["VMS Operating System Is 30 Years Old; Customers Believe It Can Last Forever"](https://www.informationweek.com/vms-operating-system-is-30-years-old-customers-believe-it-can-last-forever/d/d-id/1061051?). *InformationWeek*. Retrieved February 19, 2021.

1. **[^](#cite_ref-12)** Drew Robb (November 1, 2004). ["OpenVMS survives and thrives"](https://www.computerworld.com/article/2567299/openvms-survives-and-thrives.html). computerworld.com. Retrieved December 31, 2020.

1. **[^](#cite_ref-13)** Tao Ai Lei (May 30, 1998). ["Digital tries to salvage OpenVMS"](https://web.archive.org/web/20210925185832/https://www2.computerworld.co.nz/article/516907/digital_tries_salvage_openvms/). computerworld.co.nz. Archived from [the original](http://www2.computerworld.co.nz/article/516907/digital_tries_salvage_openvms/) on September 25, 2021. Retrieved December 31, 2020.

1. **[^](#cite_ref-14)** Jesse Lipcon (October 1997). ["OpenVMS: 20 Years of Renewal"](https://web.archive.org/web/20060217141711/http://h71000.www7.hp.com/openvms/20th/vms20/vms20.ppt). Digital Equipment Corporation. Archived from [the original](http://h71000.www7.hp.com/openvms/20th/vms20/vms20.ppt) on February 17, 2006. Retrieved February 12, 2021.

1. **[^](#cite_ref-15)** ["VAX-11/780 Hardware Handbook"](http://bitsavers.org/pdf/dec/vax/handbook/VAX_Hardware_Handbook_1979.pdf) (PDF). [Digital Equipment Corporation](/source/Digital_Equipment_Corporation). 1979. Retrieved October 17, 2022.

1. **[^](#cite_ref-RIP.CW1977_16-0)** Patrick Thibodeau (June 11, 2013). ["OpenVMS, R.I.P. 1977-2020?"](https://www.computerworld.com/article/1535041/openvms-r-i-p-1977-2020-2.html). *[Computerworld](/source/Computerworld)*. Retrieved April 27, 2024.

1. **[^](#cite_ref-17)** Tom Merritt (2012). [*Chronology of Tech History*](https://books.google.com/books?isbn=130025307X). Lulu.com. p. 104. [ISBN](/source/ISBN_(identifier)) [978-1300253075](https://en.wikipedia.org/wiki/Special:BookSources/978-1300253075).

1. **[^](#cite_ref-OLD780_18-0)** ["VAX 11/780 - OLD-COMPUTERS.COM : HISTORY / detailed info"](https://web.archive.org/web/20230926164342/https://www.old-computers.com/history/detail.asp?n=20&t=3). Archived from [the original](https://www.old-computers.com/history/detail.asp?n=20&t=3) on September 26, 2023. Retrieved April 25, 2020.

1. **[^](#cite_ref-19)** ["Supported Platforms"](https://vmssoftware.com/products/supported-platforms/). *VSI*.

1. ^ [***a***](#cite_ref-9.0_Rollout_20-0) [***b***](#cite_ref-9.0_Rollout_20-1) ["Rollout of V9.0 and Beyond"](https://vmssoftware.com/docs/may-19-2020-v9.0-rollout-and-beyond.pdf) (PDF). *VSI*. May 19, 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-NotPressRelease_21-0)** ["HP hands off OpenVMS development to VSI"](https://www.techtimes.com/articles/11907/20140801/openvms-gets-a-new-leash-on-life.htm). *Tech Times*. August 1, 2014. Retrieved April 27, 2024.

1. **[^](#cite_ref-vms-software-named-exclusive-developer_22-0)** ["VMS Software, Inc. Named Exclusive Developer of Future Versions of OpenVMS Operating System"](http://www.businesswire.com/news/home/20140731006118/en/VMS-Software-Named-Exclusive-Developer-Future-Versions) (Press release). Retrieved October 27, 2017.

1. ^ [***a***](#cite_ref-cluster-docs_23-0) [***b***](#cite_ref-cluster-docs_23-1) ["VSI Products - Clusters"](https://web.archive.org/web/20210516180900/https://vmssoftware.com/products/clusters/). *VSI*. Archived from [the original](https://vmssoftware.com/products/clusters/) on May 16, 2021. Retrieved May 4, 2021.

1. ^ [***a***](#cite_ref-Cluster_Uptime_24-0) [***b***](#cite_ref-Cluster_Uptime_24-1) ["Cluster Uptime"](http://www.openvms.org/stories.php?story=03/11/28/7758863). November 28, 2003. [Archived](https://web.archive.org/web/20120229042903/http://www.openvms.org/stories.php?story=03%2F11%2F28%2F7758863) from the original on February 29, 2012. Retrieved December 20, 2020.

1. **[^](#cite_ref-25)** ["Commerzbank Survives 9/11 with OpenVMS Clusters"](https://availabilitydigest.com/public_articles/0407/commerzbank.pdf) (PDF). July 2009. Retrieved April 27, 2024.

1. **[^](#cite_ref-26)** ["February 2018 Business & Technical Update"](https://vmssoftware.com/docs/w1_Feb2018_Update.pdf) (PDF). VSI. February 2018. Retrieved May 4, 2021.

1. **[^](#cite_ref-27)** [Cutler, Dave](/source/Dave_Cutler) (February 25, 2016). ["Dave Cutler Oral History"](https://www.youtube.com/watch?v=29RkHH-psrY). *youtube.com* (Interview). Interviewed by Grant Saviers. Computer History Museum. [Archived](https://ghostarchive.org/varchive/youtube/20211211/29RkHH-psrY) from the original on December 11, 2021. Retrieved February 26, 2021.

1. **[^](#cite_ref-bellstreckerpdp11vaxalpha_28-0)** [Bell, Gordon](/source/Gordon_Bell); Strecker, W.D. [What Have We Learned from the PDP-11 - What We Have Learned from VAX and Alpha](https://archive.computerhistory.org/resources/text/DEC/alpha/dec.alpha.bell_stecker.pdp-11_vax_and_alpha.1998.102630388.pdf) (PDF) (Report). Retrieved June 26, 2025.

1. ^ [***a***](#cite_ref-what-is-vms_29-0) [***b***](#cite_ref-what-is-vms_29-1) Stephen Hoffman (September 2006). ["What is OpenVMS? What is its history?"](https://web.archive.org/web/20210518115130/http://www.hoffmanlabs.com/vmsfaq/vmsfaq_001.html). *hoffmanlabs.com*. Archived from [the original](http://www.hoffmanlabs.com/vmsfaq/vmsfaq_001.html) on May 18, 2021. Retrieved January 3, 2021.

1. ^ [***a***](#cite_ref-vms-1.0-spd_30-0) [***b***](#cite_ref-vms-1.0-spd_30-1) ["Software Product Description – VAX/VMS Operating System, Version 1.0"](http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/AE-C770B-TE%20VAX-VMS%20Operating%20System,%20Version%201.0%20SPD%2025.1.2.pdf) (PDF). Digital Equipment Corporation. September 1978. Retrieved October 21, 2021.

1. **[^](#cite_ref-31)** ["a simple question: what the h*ll is MCR?"](https://comp.os.vms.narkive.com/N4yPsEEV/a-simple-question-what-the-h-ll-is-mcr). [Newsgroup](/source/Usenet_newsgroup): [comp.os.vms](news:comp.os.vms). September 14, 2004. Retrieved December 31, 2020.

1. **[^](#cite_ref-32)** ["Software Product Description VAX-11 RSX, Version 1.0"](http://bitsavers.org/pdf/dec/vax/vms/4.0/AE-DL72A-TE_VAX_RSX_1.0_SPD_198410.pdf) (PDF). Digital Equipment Corporation. October 1984. Retrieved September 20, 2021.

1. **[^](#cite_ref-33)** ["Hello from....well what used to be SpitBrook"](http://www.openvmshobbyist.com/forum/viewthread.php?forum_id=130&thread_id=332). *openvmshobbyist.com*. February 27, 2007. Retrieved January 24, 2021.

1. **[^](#cite_ref-34)** ["Computer system VAX/VMS"](https://web.archive.org/web/20210201143630/http://www.altiq.se/vax-vms/vax-vms-eng.html). *altiq.se*. Archived from [the original](http://www.altiq.se/vax-vms/vax-vms-eng.html) on February 1, 2021. Retrieved January 24, 2021.

1. **[^](#cite_ref-rdbmsingressybase20070613_35-0)** ["RDBMS Workshop: Ingres and Sybase"](https://archive.computerhistory.org/resources/access/text/2013/05/102702565-05-01-acc.pdf) (PDF) (Interview). Interviewed by Doug Jerger. Computer History Museum. June 13, 2007. Retrieved May 30, 2025.

1. **[^](#cite_ref-36)** Michael D Duffy (2002). [*Getting Started with OpenVMS: A Guide for New Users*](https://books.google.com/books?isbn=0080507352). Elsevier. [ISBN](/source/ISBN_(identifier)) [978-0080507354](https://en.wikipedia.org/wiki/Special:BookSources/978-0080507354).

1. **[^](#cite_ref-37)** ["Micro VMS operating system"](https://books.google.com/books?id=aqjZTUJlyygC). *[Computerworld](/source/Computerworld)*. June 18, 1984. p. 7. The Micro VMS operating system announced last week by Digital Equipment Corp. for its Microvax I family of microcomputers is a prepackaged version of ...

1. **[^](#cite_ref-DEC.prof_38-0)** Kathleen D. Morse. "The VMS/MicroVMS merge". *DEC Professional Magazine*. pp. 74–84.

1. ^ [***a***](#cite_ref-vms-5.0-rel-notes_39-0) [***b***](#cite_ref-vms-5.0-rel-notes_39-1) ["VMS Version 5.0 Release Notes"](http://bitsavers.trailing-edge.com/pdf/dec/vax/vms/5.0/AA-LB22A-TE_VMS_5.0_Release_Notes_198804.pdf) (PDF). DEC. April 1988. Retrieved July 21, 2021.

1. **[^](#cite_ref-40)** Bob McCormick (January 11, 1989). ["DECUServe WORKSTATIONS Conference Topic 8"](https://decuserve.com/anon/htnotes/note?f1=WORKSTATIONS&f2=8.0). *decuserve.com*. Retrieved May 26, 2026.{{[cite web](https://en.wikipedia.org/wiki/Template:Cite_web)}}: CS1 maint: url-status ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_url-status))

1. **[^](#cite_ref-41)** ["Office Archaeology"](http://blog.nozell.com/2004/02/office-archeology.html). *blog.nozell.com*. February 24, 2004. Retrieved December 22, 2020.

1. **[^](#cite_ref-42)** ["Software Product Description - Desktop-VMS, Version 1.2"](https://web.archive.org/web/20000816181649/http://www.digital.com/info/SP25F4/SP25F4PF.PDF) (PDF). Digital. January 1991. Archived from [the original](http://www.digital.com/info/SP25F4/SP25F4PF.PDF) (PDF) on August 16, 2000. Retrieved February 2, 2022.

1. **[^](#cite_ref-43)** ["OpenVMS pages of proGIS Germany"](http://vaxarchive.org/hardware/vms-hw.html). *vaxarchive.org*. Retrieved December 22, 2020.

1. **[^](#cite_ref-44)** D.O. Andrievskaya, ed. (May 1989). ["Computer Complexes, Technical Equipment, Software And Support Of The System Of Small Electronic Computer Machines (SM Computer)"](http://oldpc.su/lib/gsp/sm89.pdf) (PDF) (in Russian). Soviet Union Research Institute of Information and Economics. Retrieved October 16, 2021.

1. **[^](#cite_ref-45)** Prokhorov N.L.; Gorskiy V.E. ["Basic software for 32-bit SM computer models"](http://www.swsys.ru/index.php?page=article&id=1480#). *Software Systems Journal* (in Russian). **1988** (3). Retrieved October 15, 2021.

1. **[^](#cite_ref-46)** Egorov G.A.; Ostapenko G.P.; Stolyar N.G.; Shaposhnikov V.A. ["Multifunctional operating system that supports virtual memory for 32-bit computers"](http://www.swsys.ru/index.php?page=article&id=1491#). *Software Systems Journal* (in Russian). **1988** (4). Retrieved October 15, 2021.

1. **[^](#cite_ref-47)** ["Installing OS MOS-32M"](https://rtk.mirrors.pdp-11.ru/_vax/_MOC-32/MOC-32M45/moc-32m-install-1.1.pdf) (PDF). *pdp-11.ru* (in Russian). June 16, 2012. [Archived](https://web.archive.org/web/20211027181221/https://mirrors.pdp-11.ru/_vax__/_MOC-32/MOC-32M45/moc-32m-install-1.1.pdf) (PDF) from the original on October 27, 2021. Retrieved October 15, 2021.

1. **[^](#cite_ref-48)** ["VMS Version 5.0 Release Notes"](http://www.bitsavers.org/pdf/dec/vax/vms/5.0/AA-LB22A-TE_VMS_5.0_Release_Notes_198804.pdf) (PDF). Digital Equipment Corporation. April 1988. Retrieved October 27, 2021.

1. **[^](#cite_ref-DuffB_49-0)** ["Digital Introduces First Generation of OpenVMS Alpha-Ready Systems"](https://tech-insider.org/vms/research/1992/0715.html). Digital Equipment Corporation. July 15, 1992. Retrieved January 25, 2021.

1. **[^](#cite_ref-POSix_50-0)** ["OpenVMS Definition from PC Magazine Encyclopedia"](https://www.pcmag.com/encyclopedia/term/48503/openvms).

1. **[^](#cite_ref-51)** Arne Vajhøj (November 29, 1999). ["OpenVMS FAQ - What is the difference between VMS and OpenVMS?"](https://web.archive.org/web/20210924175454/http://www.vaxmacro.de/ovmsfaq.html). *vaxmacro.de*. Archived from [the original](http://www.vaxmacro.de/ovmsfaq.html) on September 24, 2021. Retrieved January 25, 2021.

1. **[^](#cite_ref-52)** ["History of the Vernon the VMS shark"](http://www.vaxination.ca/vms/shark/history.html). *vaxination.ca*. Retrieved January 24, 2021.

1. **[^](#cite_ref-53)** Dave Cutler (May 30, 1988). ["DECwest/SDT Agenda"](http://www.bitsavers.org/pdf/dec/prism/memos/880530_Cutler_PRISM_vs_MIPS.pdf) (PDF). *bitsavers.org*.

1. **[^](#cite_ref-supnik-alpha_54-0)** ["EV-4 (1992)"](http://simh.trailing-edge.com/semi/ev4.html). February 24, 2008.

1. ^ [***a***](#cite_ref-ieee-alpha_55-0) [***b***](#cite_ref-ieee-alpha_55-1) Comerford, R. (July 1992). "How DEC developed Alpha". *IEEE Spectrum*. **29** (7): 26–31. [Bibcode](/source/Bibcode_(identifier)):[1992IEEES..29g..26C](https://ui.adsabs.harvard.edu/abs/1992IEEES..29g..26C). [doi](/source/Doi_(identifier)):[10.1109/6.144508](https://doi.org/10.1109%2F6.144508).

1. **[^](#cite_ref-56)** ["Managing Technological Leaps: A study of DEC's Alpha Design Team"](https://dspace.mit.edu/bitstream/handle/1721.1/48380/managingtechnolo00katz.pdf) (PDF). April 1993.

1. **[^](#cite_ref-57)** Supnik, Robert M. (1993). ["Digital's Alpha project"](https://doi.org/10.1145%2F151220.151223). *Communications of the ACM*. **36** (2): 30–32. [doi](/source/Doi_(identifier)):[10.1145/151220.151223](https://doi.org/10.1145%2F151220.151223). [ISSN](/source/ISSN_(identifier)) [0001-0782](https://search.worldcat.org/issn/0001-0782). [S2CID](/source/S2CID_(identifier)) [32694010](https://api.semanticscholar.org/CorpusID:32694010).

1. ^ [***a***](#cite_ref-ia64-port_58-0) [***b***](#cite_ref-ia64-port_58-1) [***c***](#cite_ref-ia64-port_58-2) Clair Grant (June 2005). ["Porting OpenVMS to HP Integrity Servers"](http://www.decus.de/events/alphamigration/vortraege/porting_openvms_to_integrity.pdf) (PDF). *OpenVMS Technical Journal*. **6**.

1. ^ [***a***](#cite_ref-axp-port_59-0) [***b***](#cite_ref-axp-port_59-1) Nancy P. Kronenberg; Thomas R. Benson; Wayne M. Cardoza; Ravindran Jagannathan; Benjamin J. Thomas III (1992). ["Porting OpenVMS from VAX to Alpha AXP"](https://vmssoftware.com/docs/dtj-v04-04-1992.pdf) (PDF). *Digital Technical Journal*. **4** (4): 111–120. Retrieved April 27, 2024.

1. ^ [***a***](#cite_ref-OpenVMS_VAX_and_Alpha_Compatibility_60-0) [***b***](#cite_ref-OpenVMS_VAX_and_Alpha_Compatibility_60-1) ["OpenVMS Compatibility Between VAX and Alpha"](https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-c04623258). Digital Equipment Corporation. May 1995. Retrieved October 22, 2021.

1. **[^](#cite_ref-61)** ["Extending OpenVMS for 64-bit Addressable Virtual Memory"](https://vmssoftware.com/docs/dtj-v08-02-1996.pdf) (PDF). *Digital Technical Journal*. **8** (2): 57–71. 1996. [S2CID](/source/S2CID_(identifier)) [9618620](https://api.semanticscholar.org/CorpusID:9618620).

1. **[^](#cite_ref-62)** ["The OpenVMS Mixed Pointer Size Environment"](https://web.archive.org/web/20200219001633/https://pdfs.semanticscholar.org/8d96/bbba019c43e80f059825311b67c975a0fede.pdf) (PDF). *Digital Technical Journal*. **8** (2): 72–82. 1996. [S2CID](/source/S2CID_(identifier)) [14874367](https://api.semanticscholar.org/CorpusID:14874367). Archived from [the original](https://pdfs.semanticscholar.org/8d96/bbba019c43e80f059825311b67c975a0fede.pdf) (PDF) on February 19, 2020.

1. **[^](#cite_ref-prog-concepts-i_63-0)** ["VSI OpenVMS Programming Concepts Manual, Vol. 1"](https://vmssoftware.com/docs/VSI_PROGRAM_CONCEPTS_VOL_I.pdf) (PDF). VSI. April 2020. Retrieved October 7, 2020.

1. **[^](#cite_ref-galaxy-docs_64-0)** ["HP OpenVMS Alpha Partitioning and Galaxy Guide"](https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-c04621422). HP. September 2003. Retrieved October 22, 2021.

1. **[^](#cite_ref-65)** James Niccolai (October 14, 1998). ["Compaq details strategy for OpenVMS"](https://web.archive.org/web/20230404095822/https://www.arnnet.com.au/article/111492/compaq_details_strategy_openvms/). Australian Reseller News. Archived from [the original](https://www.arnnet.com.au/article/111492/compaq_details_strategy_openvms/) on April 4, 2023. Retrieved January 14, 2021.

1. **[^](#cite_ref-66)** ["Compaq OpenVMS Times"](https://web.archive.org/web/20060302213751/http://h71000.www7.hp.com/openvmstimes/openvmstimes.pdf) (PDF). January 2002. Archived from [the original](http://h71000.www7.hp.com/openvmstimes/openvmstimes.pdf) (PDF) on March 2, 2006.

1. **[^](#cite_ref-67)** Andrew Orlowski (June 25, 2001). ["Farewell then, Alpha – Hello, Compaq the Box Shifter"](https://www.theregister.com/2001/06/25/farewell_then_alpha_hello_compaq/). *theregister.com*. Retrieved December 21, 2020.

1. **[^](#cite_ref-68)** Sue Skonetski (January 31, 2003). ["OpenVMS Boots on Itanium on Friday Jan 31"](https://groups.google.com/g/comp.os.vms/c/alWtue7YLUw/m/x1_GVv1eFfEJ). [Newsgroup](/source/Usenet_newsgroup): [comp.os.vms](news:comp.os.vms). Retrieved December 21, 2020.

1. **[^](#cite_ref-69)** ["HP C Installation Guide for OpenVMS Industry Standard 64 Systems"](https://vmssoftware.com/docs/ig_bvbv.pdf) (PDF). HP. June 2007. Retrieved March 2, 2021.

1. **[^](#cite_ref-70)** Thomas Siebold (2005). ["OpenVMS Integrity Boot Environment"](http://www.decus.de/slides/sy2005/06_04/2g04.pdf) (PDF). *decus.de*. Retrieved December 21, 2020.

1. ^ [***a***](#cite_ref-swis_71-0) [***b***](#cite_ref-swis_71-1) [***c***](#cite_ref-swis_71-2) Camiel Vanderhoeven (October 8, 2017). [*Re-architecting SWIS for X86-64*](https://www.youtube.com/watch?v=U8kcfvJ1Iec). *[YouTube](/source/YouTube)*. [Archived](https://ghostarchive.org/varchive/youtube/20211211/U8kcfvJ1Iec) from the original on December 11, 2021. Retrieved October 21, 2021.

1. **[^](#cite_ref-72)** Gaitan D’Antoni (2005). ["Porting OpenVMS Applications to Itanium"](http://www.hp-user-society.de/events/alphamigration/vortraege/porting_openvms_applications_to_itanium.pdf) (PDF). *hp-user-society.de*. Retrieved December 21, 2020.

1. **[^](#cite_ref-73)** ["OpenVMS floating-point arithmetic on the Intel Itanium architecture"](http://www.decus.de/events/alphamigration/vortraege/i64-floating-pt-wp.pdf) (PDF). *decus.de*. 2003. Retrieved December 21, 2020.

1. **[^](#cite_ref-74)** Thomas Siebold (2005). ["OpenVMS Moving Custom Code"](http://www.decus.de/slides/sy2005/06_04/2g05.pdf) (PDF). *decus.de*. Retrieved December 21, 2020.

1. **[^](#cite_ref-75)** Paul Lacombe (2005). ["HP OpenVMS Strategy and Futures"](https://web.archive.org/web/20210207063543/http://de.openvms.org/TUD2005/12_Open_VMS_Strategy_Paul_Lacombe.pdf) (PDF). *de.openvms.org*. Archived from [the original](http://de.openvms.org/TUD2005/12_Open_VMS_Strategy_Paul_Lacombe.pdf) (PDF) on February 7, 2021. Retrieved December 21, 2020.

1. **[^](#cite_ref-76)** ["VMS Software, Inc. Named Exclusive Developer of Future Versions of OpenVMS Operating System"](https://web.archive.org/web/20140810031139/http://www.businesswire.com/news/home/20140731006118/en/VMS-Software-Named-Exclusive-Developer-Future-Versions#.U-bjA7xxfZt) (Press release). July 31, 2014. Archived from [the original](http://www.businesswire.com/news/home/20140731006118/en/VMS-Software-Named-Exclusive-Developer-Future-Versions) on August 10, 2014.

1. ^ [***a***](#cite_ref-vms-roadmap-12-2019_77-0) [***b***](#cite_ref-vms-roadmap-12-2019_77-1) ["OpenVMS Rolling Roadmap"](https://web.archive.org/web/20200610041353/https://vmssoftware.com/pdfs/VSI_Roadmap_20191209.pdf) (PDF). VSI. December 2019. Archived from [the original](https://vmssoftware.com/pdfs/VSI_Roadmap_20191209.pdf) (PDF) on June 10, 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-78)** ["VSI V9.0 Q&A"](https://vmssoftware.com/about/v9-qa/). *VSI*. Retrieved April 27, 2024.

1. **[^](#cite_ref-79)** VSI (June 1, 2021). [*OpenVMS x64 Atom Project*](https://www.youtube.com/watch?v=3H6AJigJnNs). *[YouTube](/source/YouTube)*. [Archived](https://ghostarchive.org/varchive/youtube/20211211/3H6AJigJnNs) from the original on December 11, 2021. Retrieved June 2, 2021.

1. **[^](#cite_ref-80)** [*2017 LLVM Developers' Meeting: J. Reagan "Porting OpenVMS using LLVM"*](https://www.youtube.com/watch?v=xTaBkCBYskA). *[YouTube](/source/YouTube)*. October 31, 2017. [Archived](https://ghostarchive.org/varchive/youtube/20211211/xTaBkCBYskA) from the original on December 11, 2021.

1. **[^](#cite_ref-81)** ["State of the Port to x86_64 January 2017"](https://web.archive.org/web/20191104221854/http://www.vmssoftware.com/pdfs/State_of_Port_20170105.pdf) (PDF). January 6, 2017. Archived from [the original](http://www.vmssoftware.com/pdfs/State_of_Port_20170105.pdf) (PDF) on November 4, 2019.

1. **[^](#cite_ref-82)** ["VMS Software Inc. Announces First Boot on x86 Architecture"](https://vmssoftware.com/about/news/2019-05-14-vms-software-inc-announces-first-boot-on-x86-architecture/). *VSI*. May 14, 2019. Retrieved May 4, 2021.

1. **[^](#cite_ref-state-of-the-port_83-0)** ["State of the Port"](https://web.archive.org/web/20210418211710/https://vmssoftware.com/about/state-of-the-port/). *VSI*. Archived from [the original](https://vmssoftware.com/updates/state-of-the-port/) on April 18, 2021. Retrieved April 16, 2021.

1. ^ [***a***](#cite_ref-vms-9.1_84-0) [***b***](#cite_ref-vms-9.1_84-1) ["OpenVMS 9.1"](https://web.archive.org/web/20210630172618/https://vmssoftware.com/about/openvmsv9-1/). *VSI*. June 30, 2021. Archived from [the original](https://vmssoftware.com/about/openvmsv9-1/) on June 30, 2021. Retrieved June 30, 2021.

1. ^ [***a***](#cite_ref-vsi-9.1-A_85-0) [***b***](#cite_ref-vsi-9.1-A_85-1) ["VMS Software Releases OpenVMS V9.1-A"](https://vmssoftware.com/about/news/2021-09-30-openvms-9/). *VSI*. September 30, 2021. Retrieved September 30, 2021.

1. **[^](#cite_ref-mica-business-plan_86-0)** Catherine Richardson; Terry Morris; Rockie Morgan; Reid Brown; Donna Meikle (March 1987). ["MICA Software Business Plan"](http://www.bitsavers.org/pdf/dec/prism/mica/Mica_Software_Business_Plan_Mar87.pdf) (PDF). *Bitsavers*. Retrieved January 4, 2021.

1. **[^](#cite_ref-87)** Zachary, G. Pascal (2014). [*Showstopper!: The Breakneck Race to Create Windows NT and the Next Generation at Microsoft*](https://books.google.com/books?id=o2IkAwAAQBAJ&q=%22Dave+Cutler%22+march+13&pg=PT9). Open Road Media. [ISBN](/source/ISBN_(identifier)) [978-1-4804-9484-8](https://en.wikipedia.org/wiki/Special:BookSources/978-1-4804-9484-8). Retrieved January 4, 2021.

1. **[^](#cite_ref-88)** Mark Russinovich (October 30, 1998). ["Windows NT and VMS: The Rest of the Story"](https://www.itprotoday.com/compute-engines/windows-nt-and-vms-rest-story). *ITPro Today*. Retrieved January 4, 2021.

1. **[^](#cite_ref-89)** Eugenia Loli (November 23, 2004). ["FreeVMS 0.1.0 Released"](https://www.osnews.com/story/8953/freevms-010-released/). *OSnews*. Retrieved April 2, 2022.

1. **[^](#cite_ref-freevms-homepage_90-0)** ["FreeVMS official web page"](https://web.archive.org/web/20180908204358/http://www.freevms.net/). Archived from [the original](http://www.freevms.net/) on September 8, 2018.

1. **[^](#cite_ref-wiecek1992_91-0)** Wiecek, Cheryl A.; Kaler, Christopher G.; Fiorelli, Stephen; Davenport, Jr., William C.; Chen, Robert C. (April 1992). ["A Model and Prototype of VMS Using the Mach 3.0 Kernel"](https://archive.org/details/1992-proceedings-microkernels-seattle/page/187/mode/1up). *Proceedings of the USENIX Workshop on Micro-Kernels and Other Kernel Architectures*: 187–203. Retrieved September 20, 2021.

1. ^ [***a***](#cite_ref-idsm-5.2_92-0) [***b***](#cite_ref-idsm-5.2_92-1) [***c***](#cite_ref-idsm-5.2_92-2) [***d***](#cite_ref-idsm-5.2_92-3) [***e***](#cite_ref-idsm-5.2_92-4) [***f***](#cite_ref-idsm-5.2_92-5) Ruth E. Goldenberg; Lawrence J. Kenah; Denise E. Dumas (1991). [*VAX/VMS Internals and Data Structures, Version 5.2*](https://books.google.com/books?id=D7xQAAAAMAAJ). Digital Press. [ISBN](/source/ISBN_(identifier)) [978-1555580599](https://en.wikipedia.org/wiki/Special:BookSources/978-1555580599).

1. ^ [***a***](#cite_ref-goatley-part-1_93-0) [***b***](#cite_ref-goatley-part-1_93-1) [***c***](#cite_ref-goatley-part-1_93-2) Hunter Goatley; Edward A. Heinrich. ["Writing VMS Privileged Code Part I: The Fundamentals, Part 1"](https://hunter.goatley.com/vms/internals1.html). *hunter.goatley.com*. Retrieved January 31, 2021.

1. **[^](#cite_ref-94)** Paul A. Karger; Mary Ellen Zurko; Douglas W. Benin; Andrew H. Mason; Clifford E. Kahnh (May 7–9, 1990). [*A VMM security kernel for the VAX architecture*](https://www.scs.stanford.edu/nyu/04fa/sched/readings/vmm.pdf) (PDF). Proceedings. 1990 IEEE Computer Society Symposium on Research in Security and Privacy. IEEE. [doi](/source/Doi_(identifier)):[10.1109/RISP.1990.63834](https://doi.org/10.1109%2FRISP.1990.63834). Retrieved January 31, 2021.

1. **[^](#cite_ref-95)** ["VSI OpenVMS System Services Reference Manual: A–GETUAI"](https://vmssoftware.com/docs/VSI_SYS_SERVICES_REF_VOL_I.PDF) (PDF). VSI. June 2020. Retrieved February 15, 2021.

1. **[^](#cite_ref-inside-vms_96-0)** Wayne Sewell (1992). [*Inside VMS: The System Manager's and System Programmer's Guide to VMS Internals*](https://books.google.com/books?id=c4UhAQAAIAAJ). Van Nostrand Reinhold. [ISBN](/source/ISBN_(identifier)) [0-442-00474-5](https://en.wikipedia.org/wiki/Special:BookSources/0-442-00474-5).

1. **[^](#cite_ref-acp-qio-doc_97-0)** ["OpenVMS I/O User's Reference Manual"](https://vmssoftware.com/docs/VSI_IO_REF.pdf) (PDF). VSI. August 2019. Retrieved January 13, 2021.

1. ^ [***a***](#cite_ref-andy-goldstein-files-11_98-0) [***b***](#cite_ref-andy-goldstein-files-11_98-1) ["Andy Goldstein on Files-11, the OpenVMS File Systems"](https://web.archive.org/web/20210112225121/https://www.youtube.com/watch?v=b0YenelPw-Y). *Official Channel*. VSI. July 25, 2019. Archived from [the original](https://www.youtube.com/watch?v=b0YenelPw-Y) on January 12, 2021. Retrieved January 3, 2021.

1. **[^](#cite_ref-99)** ["VSI OpenVMS Guide to OpenVMS File Applications"](https://vmssoftware.com/docs/VSI_Gd_to_File_Apps_23Jul19.pdf) (PDF). VSI. July 23, 2019. Retrieved January 13, 2021.

1. ^ [***a***](#cite_ref-Why_was_Spiralog_retired_100-0) [***b***](#cite_ref-Why_was_Spiralog_retired_100-1) ["Why was Spiralog retired?"](https://community.hpe.com/t5/Operating-System-OpenVMS/Why-was-Spiralog-retired/td-p/4951205). *Community – Operating System – OpenVMS*. Hewlett Packard Enterprise. January 10, 2006. Retrieved January 13, 2021.

1. **[^](#cite_ref-september-2020-roadmap_101-0)** ["VSI OpenVMS Software Roadmap 2020"](https://web.archive.org/web/20201207040724/https://vmssoftware.com/pdfs/VMS_Software_Roadmap_2020.pdf) (PDF). September 2020. Archived from [the original](https://vmssoftware.com/pdfs/VMS_Software_Roadmap_2020.pdf) (PDF) on December 7, 2020. Retrieved September 23, 2020.

1. **[^](#cite_ref-user-guide_102-0)** ["OpenVMS User's Manual"](https://vmssoftware.com/docs/VSI_USERS_MANUAL.pdf) (PDF). *VSI*. July 2020. Chapter 14, Advanced Programming with DCL. Retrieved April 9, 2021.

1. ^ [***a***](#cite_ref-dcl-supervisor-thread_103-0) [***b***](#cite_ref-dcl-supervisor-thread_103-1) Simon Clubley (July 3, 2017). ["How dangerous is it to be able to get into DCL supervisor mode?"](https://comp.os.vms.narkive.com/Wc1uHZU3/how-dangerous-is-it-to-be-able-to-get-into-dcl-supervisor-mode). [Newsgroup](/source/Usenet_newsgroup): [comp.os.vms](news:comp.os.vms). Retrieved February 1, 2021.

1. **[^](#cite_ref-104)** ["VSI OpenVMS Cluster Systems"](https://vmssoftware.com/docs/VSI_OpenVMS_Cluster_Systems.pdf) (PDF). VSI. August 2019. Retrieved January 13, 2021.

1. **[^](#cite_ref-105)** ["Building Dependable Systems: The OpenVMS Approach"](https://www.digiater.nl/openvms/doc/alpha-v8.3/ovms_archived/BUILD_DEPEND_SYS.PDF) (PDF). DEC. May 1994. Retrieved July 31, 2021.

1. **[^](#cite_ref-106)** ["DECnet for OpenVMS Guide to Networking"](https://web.archive.org/web/20210121012741/https://vmssoftware.com/docs/VSI_DECnet_IV_Gd_to_Networking.pdf) (PDF). VSI. August 2020. Archived from [the original](https://vmssoftware.com/docs/VSI_DECnet_IV_Gd_to_Networking.pdf) (PDF) on January 21, 2021. Retrieved January 14, 2021.

1. **[^](#cite_ref-107)** ["Software Product Description: DECnet-VAX, Version 1"](https://archive.org/download/bitsavers_decspd25.0_392688/25.03.01_7809_DECnet-VAX_V1.pdf) (PDF). DEC. September 1978. Retrieved May 23, 2023.

1. **[^](#cite_ref-108)** ["VSI Products - DECnet"](https://web.archive.org/web/20210127105141/https://vmssoftware.com/products/decnet/). VSI. Archived from [the original](https://vmssoftware.com/products/decnet/) on January 27, 2021. Retrieved January 14, 2021.

1. **[^](#cite_ref-109)** ["VMS/ULTRIX System Manager's Guide"](https://archive.org/details/hack42_VMS-ULTRIX_Connection_Volume_1_System_Managers_Guide). Digital Equipment Corporation. September 1990. Retrieved January 21, 2021.

1. **[^](#cite_ref-tcp-ip-services_110-0)** ["VSI OpenVMS TCP/IP User's Guide"](https://vmssoftware.com/docs/VSI_TCPIP_USERS_GD.PDF) (PDF). VSI. August 2019. Retrieved January 14, 2021.

1. **[^](#cite_ref-111)** Robert Rappaport; Yanick Pouffary; Steve Lieman; Mary J. Marotta (2004). ["Parallelism and Performance in the OpenVMS TCP/IP Kernel"](https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-c04623334). *OpenVMS Technical Journal*. **4**.

1. **[^](#cite_ref-112)** Alan Abrahams; David A. Low (1992). ["An Overview of the PATHWORKS Product Family"](https://vmssoftware.com/docs/dtj-v04-01-1992.pdf) (PDF). *Digital Technical Journal*. **4** (1): 8–14. Retrieved April 27, 2024.

1. **[^](#cite_ref-113)** Andy Goldstein (2005). ["Samba and OpenVMS"](https://web.archive.org/web/20210207063545/http://de.openvms.org/TUD2005/02_Advanced_Server_and_Samba_Andy_Goldstein.pdf) (PDF). *de.openvms.org*. Archived from [the original](http://de.openvms.org/TUD2005/02_Advanced_Server_and_Samba_Andy_Goldstein.pdf) (PDF) on February 7, 2021. Retrieved January 1, 2021.

1. **[^](#cite_ref-114)** ["Local Area Transport Network Concepts"](http://www.bitsavers.org/pdf/dec/ethernet/decserver_300/AA-LD84A-TK_LAT_Network_Concepts_Jun88.pdf) (PDF). DEC. June 1988. Retrieved January 14, 2021.

1. ^ [***a***](#cite_ref-language-1985_115-0) [***b***](#cite_ref-language-1985_115-1) [***c***](#cite_ref-language-1985_115-2) [***d***](#cite_ref-language-1985_115-3) [***e***](#cite_ref-language-1985_115-4) ["VAX/VMS Software Language and Tools Handbook"](http://bitsavers.org/pdf/dec/vax/handbook/VMS_Language_and_Tools_Handbook_1985.pdf) (PDF). *bitsavers.org*. 1985. Retrieved December 31, 2020.

1. **[^](#cite_ref-vsi-products_116-0)** ["VSI List of Products"](https://web.archive.org/web/20210516174139/https://vmssoftware.com/products/list/). *VSI*. Archived from [the original](https://vmssoftware.com/products/list/) on May 16, 2021. Retrieved May 4, 2021.

1. **[^](#cite_ref-117)** ["Lua"](https://products.vmssoftware.com/lua). *VMS Software, Inc*. Retrieved June 27, 2025.

1. **[^](#cite_ref-openvms-calling-standard_118-0)** ["VSI OpenVMS Calling Standard"](https://vmssoftware.com/docs/VSI_CALLING_STD.pdf) (PDF). January 2021. Retrieved May 4, 2021.

1. **[^](#cite_ref-119)** ["VSI OpenVMS Programming Concepts Manual, Volume II"](https://vmssoftware.com/docs/VSI_PROGRAM_CONCEPTS_VOL_II.pdf) (PDF). VSI. April 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-120)** ["SDL, LANGUAGE, Data Structure/Interface Definition Language"](https://www.digiater.nl/openvms/freeware/v30/sdl/freeware_readme.txt). *digiater.nl*. November 1996. Retrieved January 3, 2021.

1. **[^](#cite_ref-121)** ["VMS Software / Documentation"](https://docs.vmssoftware.com/). *VSI*. Retrieved May 12, 2025.

1. **[^](#cite_ref-122)** ["DECset"](https://web.archive.org/web/20210107111246/https://vmssoftware.com/products/decset/). *VSI*. Archived from [the original](https://vmssoftware.com/products/decset/) on January 7, 2021. Retrieved January 2, 2021.

1. **[^](#cite_ref-123)** ["VSI OpenVMS DCL Dictionary: A–M"](https://vmssoftware.com/docs/VSI_DCL_DICT_VOL_I.pdf) (PDF). VSI. April 2020. Retrieved January 2, 2021.

1. **[^](#cite_ref-124)** ["VSI OpenVMS Debugger Manual"](https://vmssoftware.com/docs/VSI_DEBUGGER.pdf) (PDF). VSI. June 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-125)** ["VSI OpenVMS Delta/XDelta Debugger Manual"](https://vmssoftware.com/docs/VSI_DELTA_XDELTA.pdf) (PDF). VSI. August 2019. Retrieved December 31, 2020.

1. **[^](#cite_ref-126)** ["VMS IDE"](https://marketplace.visualstudio.com/items?itemName=VMSSoftwareInc.vms-ide). *Visual Studio Marketplace*. Retrieved January 2, 2021.

1. **[^](#cite_ref-vax-info-handbook_127-0)** ["VAX/VMS Software Information Management Handbook"](http://bitsavers.trailing-edge.com/pdf/dec/vax/handbook/VMS_Information_Management_Handbook_1985.pdf) (PDF). Digital Equipment Corporation. 1985. Retrieved January 24, 2021.

1. **[^](#cite_ref-128)** Ian Smith (2004). ["Rdb's First 20 Years: Memories and Highlights"](https://web.archive.org/web/20051103112619/http://www.oracle.com/technology/products/rdb/pdf/2003_tech_forums/13_rdbs_first_20_years.pdf) (PDF). Archived from [the original](http://www.oracle.com/technology/products/rdb/pdf/2003_tech_forums/13_rdbs_first_20_years.pdf) (PDF) on November 3, 2005. Retrieved January 24, 2021.

1. **[^](#cite_ref-129)** ["Compaq ACMS for OpenVMS Getting Started"](http://odl.sysworks.biz/disk$vaxdocmar002/database/acms_v43/6621/6621pro_contents.html). Compaq. December 1999. Retrieved January 24, 2021.

1. **[^](#cite_ref-130)** ["Building Dependable Systems: The OpenVMS Approach"](https://support.hpe.com/hpesc/public/docDisplay?docId=c04622599). Digital Equipment Corporation. March 1994. Retrieved October 17, 2022.

1. **[^](#cite_ref-131)** ["Cover Letter for DECADMIRE V2.1 MUP Kit - DECADMIRE V2.1A"](http://h30266.www3.hpe.com/MasterIndex/cover_letter/cover_letter_0071573c.txt). Digital Equipment Corporation. 1995. Retrieved January 24, 2021.[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*]

1. **[^](#cite_ref-132)** Kevin Duffy; Philippe Vigier (2004). ["Oracle Rdb Status and Direction"](http://www.decus.de/slides/sy2004/21_04/2p06.pdf) (PDF). Retrieved January 24, 2021.

1. **[^](#cite_ref-133)** Larry Goelz; John Paladino (May 31, 1999). ["Cover Letter re DSM"](http://h30266.www3.hpe.com/masterindex/cover_letter/cover_letter_013a1ce4.txt). Compaq. Retrieved January 24, 2021.[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*]

1. **[^](#cite_ref-134)** Neil Rieck (June 29, 2020). ["OpenVMS Notes MySQL and MariaDB"](https://web.archive.org/web/20210131062246/http://www3.sympatico.ca/n.rieck/docs/openvms_notes_mysql_mariardb.html). Archived from [the original](http://www3.sympatico.ca/n.rieck/docs/openvms_notes_mysql_mariardb.html) on January 31, 2021. Retrieved January 24, 2021.

1. **[^](#cite_ref-135)** Bengt Gunne (2017). ["Mimer SQL on OpenVMS Present and Future"](https://www.vmsconsultancy.com/download/NL-VMSUpdate-2017/MimerSQL%20VMSSIG%20Holland.pdf) (PDF). Retrieved April 27, 2024.

1. **[^](#cite_ref-136)** ["Mimer SQL is now available for OpenVMS on x86"](https://developer.mimer.com/mimer-sql-is-now-available-for-openvms-on-x86/). Mimer Information Technology AB. 2023.

1. **[^](#cite_ref-137)** ["Rocket Software System 1032"](https://web.archive.org/web/20210122232806/https://www.rocketsoftware.com/products/rocket-m204/rocket-system-1032). Rocket Software. Archived from [the original](https://www.rocketsoftware.com/products/rocket-m204/rocket-system-1032) on January 22, 2021. Retrieved January 24, 2021.

1. **[^](#cite_ref-138)** Hoffman, Stephen; Anagnostopoulos, Paul (1999). *Writing Real Programs in DCL* (2nd ed.). Digital Press. [ISBN](/source/ISBN_(identifier)) [1-55558-191-9](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-191-9).

1. **[^](#cite_ref-139)** ["Software Product Description HP DECforms for OpenVMS, Version 4.0"](http://h30266.www3.hpe.com/PDFs/HPFMS25.pdf) (PDF). *Hewlett Packard Enterprise*. August 2006. Retrieved January 1, 2021.[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*]

1. **[^](#cite_ref-140)** ["Software Product Description HP FMS for OpenVMS, Version 2.5"](http://h30266.www3.hpe.com/PDFs/SPDDecforms40.pdf) (PDF). *Hewlett Packard Enterprise*. January 2005. Retrieved January 1, 2021.[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*]

1. **[^](#cite_ref-141)** ["Compaq TDMS for OpenVMS VAX, Version 1.9B"](http://h30266.www3.hpe.com/PDFs/TDMSforVAXV19B.pdf) (PDF). *Hewlett Packard Enterprise*. July 2002. Retrieved January 1, 2021.[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*]

1. **[^](#cite_ref-142)** ["OpenVMS RTL Screen Management (SMG$) Manual"](https://web.archive.org/web/20201204210834/http://h30266.www3.hpe.com/odl/vax/opsys/vmsos73/vmsos73/5935/5935pro_contents.html). *Hewlett Packard Enterprise*. 2001. Archived from [the original](http://h30266.www3.hpe.com/odl/vax/opsys/vmsos73/vmsos73/5935/5935pro_contents.html) on December 4, 2020. Retrieved January 1, 2021.

1. **[^](#cite_ref-143)** Rick Spitz; Peter George; Stephen Zalewski (1986). ["The Making of a Micro VAX Workstation"](http://www.bitsavers.org/pdf/dec/dtj/dtj_v01-02_mar1986.pdf) (PDF). *Digital Technical Journal*. **1** (2). Retrieved October 21, 2021.

1. **[^](#cite_ref-144)** ["MicroVMS Workstation Graphics Programming Guide"](http://www.bitsavers.org/pdf/dec/vax/vms/vms_workstation/AL-GI10B-TN_MicroVMS_Workstation_Graphics_Programming_Guide_May1986.pdf) (PDF). Digital Equipment Corporation. May 1986. Retrieved October 21, 2021.

1. **[^](#cite_ref-145)** Fred Kleinsorge (January 4, 2007). ["comp.os.vms - Dec VWS Internals"](https://comp.os.vms.narkive.com/wjLKqt6l/dec-vws-internals#post3). [Newsgroup](/source/Usenet_newsgroup): [comp.os.vms](news:comp.os.vms). Retrieved February 27, 2021.

1. **[^](#cite_ref-146)** Scott A. McGregor (1990). ["An Overview of the DECwindows Architecture"](http://www.bitsavers.org/pdf/dec/dtj/dtj_v02-03_1990.pdf) (PDF). *Digital Technical Journal*. **2** (3). Digital Equipment Corporation. Retrieved October 21, 2021.

1. ^ [***a***](#cite_ref-vaxmacro-release_147-0) [***b***](#cite_ref-vaxmacro-release_147-1) [***c***](#cite_ref-vaxmacro-release_147-2) [***d***](#cite_ref-vaxmacro-release_147-3) ["(Open)VMS(/ VAX), Version overview"](https://web.archive.org/web/20201022122158/http://www.vaxmacro.de/vvo.html). *vaxmacro.de*. Archived from [the original](http://www.vaxmacro.de/vvo.html) on October 22, 2020. Retrieved October 21, 2021.

1. **[^](#cite_ref-148)** ["Migrating VWS/UIS Applications to DECwindows?"](https://web.archive.org/web/20180915122243/http://h41379.www4.hpe.com/wizard/wiz_9916.html). *HP OpenVMS ask the wizard*. November 9, 2004. Archived from [the original](http://h41379.www4.hpe.com/wizard/wiz_9916.html) on September 15, 2018.

1. **[^](#cite_ref-149)** Janet Dobbs (August 1989). ["Strategies for Writing Graphical UNIX Applications Productively and Portably"](https://www.tuhs.org/Archive/Documentation/AUUGN/AUUGN-V10.4.pdf) (PDF). *AUUG Newsletter*. **10** (4): 50. Retrieved December 29, 2021.

1. **[^](#cite_ref-150)** ["Using DECwindows Motif for OpenVMS"](https://vmssoftware.com/docs/VSI_DECW_USER_GD.pdf) (PDF). *VSI*. October 2019. Retrieved October 21, 2020.

1. **[^](#cite_ref-151)** S. Kadantsev; M. Mouat. [*Early Experience With DECwindows/Motif In the TRIUMF Central Control System*](https://web.archive.org/web/20171125063526/http://accelconf.web.cern.ch/AccelConf/c92/papers/xi-11.pdf) (PDF). 13th International Conference on Cyclotrons and their Applications. pp. 676–677. Archived from [the original](https://accelconf.web.cern.ch/accelconf/c92/papers/xi-11.pdf) (PDF) on November 25, 2017. Retrieved August 28, 2019.

1. **[^](#cite_ref-152)** ["Getting Started With the New Desktop"](http://odl.sysworks.biz/disk$axpdocdec023/office/dwmot126/vmsdw126/gettingstarted/getting_started.html). Digital Equipment Corporation. May 1996. Retrieved October 21, 2021.

1. **[^](#cite_ref-153)** [OpenGL Frequently Asked Questions (FAQ) \[1/3\]](http://www.faqs.org/faqs/graphics/opengl-faq/part1/). Faqs.org. Retrieved on July 17, 2013.

1. **[^](#cite_ref-154)** ["Software Product Description VSI Graphical Kernel System"](https://vmssoftware.com/docs/VSI_gks_spd.pdf) (PDF). VSI. 2017. Retrieved January 2, 2021.

1. **[^](#cite_ref-155)** ["Software Product Description DEC PHIGS Version 3.1 for OpenVMS VAX"](http://h30266.www3.hpe.com/PDFs/DECPhigsV31forVAX.pdf) (PDF). *Hewlett Packard Enterprise*. April 1995. Retrieved January 2, 2021.[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*]

1. **[^](#cite_ref-guide-to-system-security_156-0)** ["VSI OpenVMS Guide to System Security"](https://vmssoftware.com/docs/VSI_System_Security_Manual.pdf) (PDF). VSI. December 2019. Retrieved April 26, 2021.

1. **[^](#cite_ref-157)** National Computer Security Center (NCSC) Trusted Product Evaluation List (TPEL)

1. **[^](#cite_ref-158)** ["HP OpenVMS Guide to System Security"](https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-c04621379). Hewlett Packard. September 2003. Retrieved October 21, 2021.

1. **[^](#cite_ref-159)** Green, James L.; Sisson, Patricia L. (June 1989). ["The "Father Christmas" Worm"](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920019024.pdf) (PDF). *12th National Computer Security Conference Proceedings*: 19024. [Bibcode](/source/Bibcode_(identifier)):[1989ntrs.rept19024G](https://ui.adsabs.harvard.edu/abs/1989ntrs.rept19024G). Retrieved November 23, 2015.

1. **[^](#cite_ref-160)** Kevin Rich (November 2004). ["Security Audit on OpenVMS: An Internal Auditor's Perspective"](https://www.giac.org/paper/gsna/176/security-audit-openvms-internal-auditors-perspective/106696). SANS Institute. Retrieved July 21, 2021.

1. **[^](#cite_ref-161)** Claes Nyberg; Christer Oberg; James Tusini (January 20, 2011). ["DEFCON 16: Hacking OpenVMS"](https://www.youtube.com/watch?v=Xf7gVma6_3g). *[YouTube](/source/YouTube)*. [Archived](https://ghostarchive.org/varchive/youtube/20211211/Xf7gVma6_3g) from the original on December 11, 2021. Retrieved July 21, 2021.

1. **[^](#cite_ref-162)** Stoll, Clifford (1989). *The Cuckoo's Egg : tracking a spy through the maze of computer espionage* (1st ed.). New York: Doubleday. [ISBN](/source/ISBN_(identifier)) [0-385-24946-2](https://en.wikipedia.org/wiki/Special:BookSources/0-385-24946-2).

1. **[^](#cite_ref-163)** On the internal workings of the CTRL-Y mechanism, see: OpenVMS AXP Internals and Data Structures, Version 1.5, sections 30.6.5.1 (CTRL/Y Processing) and 30.6.5.4 (CONTINUE Command) at pp. 1074–1076.

1. **[^](#cite_ref-164)** John Leyden (February 6, 2018). ["Ghost in the DCL shell: OpenVMS, touted as ultra reliable, had a local root hole for 30 years"](https://www.theregister.com/2018/02/06/openvms_vulnerability/). *theregister.com*. Retrieved January 13, 2021.

1. **[^](#cite_ref-165)** Digital Equipment Corporation (1994). *Software Product Description - POSIX for OpenVMS 2.0*.

1. **[^](#cite_ref-166)** ["OpenVMS Alpha Version 7.3-1 New Features and Documentation Overview Begin Index"](https://www.itec.suny.edu/scsys/vms/OVMSDOC0731/731final/6657/6657pro_008.html). June 2002.[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot)*]

1. **[^](#cite_ref-167)** ["GNV"](https://products.vmssoftware.com/gnv). *VSI Products*. Retrieved June 27, 2025.

1. **[^](#cite_ref-168)** ["ϕnix: a Unix emulator for VAX/VMS"](https://web.archive.org/web/20040122172302/https://www.caam.rice.edu/caam/trs/82/TR82-08.pdf) (PDF). August 10, 1987. Archived from [the original](https://www.caam.rice.edu/caam/trs/82/TR82-08.pdf) (PDF) on January 22, 2004.

1. **[^](#cite_ref-169)** ["Compaq and DECUS expand Free License OpenVMS Hobbyist Program"](http://www.openvmshobbyist.com/openvms_history/hobbyist_history/hobbyist_faq/hobby.html). Compaq. March 10, 1999. Retrieved August 1, 2021.

1. **[^](#cite_ref-170)** ["Hobbyist Program"](http://www.process.com/resources/openvms/hobbyist.html). *Process Software*. Retrieved April 24, 2020.

1. **[^](#cite_ref-171)** Bill Pedersen; John Malmberg. ["VMS Hardware"](https://sourceforge.net/p/vms-ports/wiki/VMSHardware/). *vms-ports*. Retrieved July 30, 2021.

1. **[^](#cite_ref-172)** ["HPE sets end date for hobbyist licenses for OpenVMS"](https://web.archive.org/web/20200704031854/https://legacyos.org/hpe-sets-end-date-for-hobbyist-licenses-for-openvms/). Archived from [the original](https://legacyos.org/hpe-sets-end-date-for-hobbyist-licenses-for-openvms/) on July 4, 2020. Retrieved July 4, 2020.

1. **[^](#cite_ref-173)** ["VMS Software Announces Community License"](https://vmssoftware.com/about/news/2020-04-22-vsi-announces-community-license/). *VSI*. April 22, 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-174)** ["VMS Software Community License Available"](https://vmssoftware.com/about/news/2020-07-28-community-license/). *VSI*. July 28, 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-175)** ["VSI Announces Community License Updates"](https://vmssoftware.com/about/news/2020-06-11-community-license-updates/). *VSI*. June 11, 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-176)** ["HP OpenVMS Systems - OpenVMS Release History"](https://web.archive.org/web/20181007091949/http://h41379.www4.hpe.com/openvms/os/openvms-release-history.html). June 21, 2010. Archived from [the original](http://h41379.www4.hpe.com/openvms/os/openvms-release-history.html) on October 7, 2018.

1. **[^](#cite_ref-177)** ["OpenVMS – A guide to the strategy and roadmap"](https://vmssoftware.com/about/roadmap/). *VSI*. Retrieved September 27, 2021.

1. **[^](#cite_ref-178)** ["HP OpenVMS Systems - Supported Software Versions - January 2014"](https://web.archive.org/web/20181014105654/http://h41379.www4.hpe.com/openvms/openvms_supportchart.html). Archived from [the original](http://h41379.www4.hpe.com/openvms/openvms_supportchart.html) on October 14, 2018.

1. **[^](#cite_ref-vsi-roadmap-2021_179-0)** ["VSI OpenVMS Software Roadmap 2021"](https://vmssoftware.com/docs/VMS_Software_Roadmap_2021.pdf) (PDF). *VSI*. Retrieved September 30, 2021.

1. **[^](#cite_ref-180)** ["OpenVMS Software Technical Support Service"](https://ftp.hp.com/pub/services/software/info/ovms.pdf) (PDF). *hp.com*. Hewlett Packard. October 2003. Retrieved February 1, 2022.

1. **[^](#cite_ref-181)** ["OpenVMS Release History"](http://www.bitsavers.org/pdf/dec/vax/vms/openvms-release-history.txt). *Bitsavers*. HP. Retrieved January 23, 2022.

1. ^ [***a***](#cite_ref-vms-x0.5_182-0) [***b***](#cite_ref-vms-x0.5_182-1) Andy Goldstein (September 16, 1997). ["When Did VMS First Come Out?"](https://groups.google.com/g/comp.os.vms/c/h3S9j5Q2LKU/m/v7ZNw_9Bja4J). [Newsgroup](/source/Usenet_newsgroup): [comp.os.vms](news:comp.os.vms). Retrieved March 5, 2022.

1. ^ [***a***](#cite_ref-vms-1.5_184-0) [***b***](#cite_ref-vms-1.5_184-1) [***c***](#cite_ref-vms-1.5_184-2) *VAX/VMS Release Notes Version 1.5*. DEC. February 1979. AA-D015B-TE.

1. **[^](#cite_ref-187)** *VAX/VMS Release Notes Version 1.6*. DEC. August 1979. AA-J039A-TE.

1. **[^](#cite_ref-188)** ["VAX/VMS Release Notes Version 3.0"](http://www.bitsavers.org/pdf/dec/vax/vms/3.0/AA-D015D-TE_VAX-VMS_Release_Notes_V3.0_May82.pdf) (PDF). DEC. May 1982. AA-D015D-TE. Retrieved February 6, 2022.

1. **[^](#cite_ref-190)** ["VAX/VMS Internals and Data Structures"](http://www.bitsavers.org/pdf/dec/vax/vms/2.2/AA-K785A-TE_VAX_VMS_2.2_Internals_and_Data_Structures_Apr81.pdf) (PDF). DEC. April 1981. Retrieved February 6, 2022.

1. **[^](#cite_ref-191)** ["VAX-11 Information Directory and Index"](http://www.bitsavers.org/pdf/dec/vax/vms/2.3/AA-D016D-TE_VAX-11_2.3_Information_Directory_and_Index_May81.pdf) (PDF). DEC. May 1981. AA-D016D-TE. Retrieved February 6, 2022.

1. **[^](#cite_ref-192)** ["GRPNAM SECURITY HOLE IN LOGIN"](http://www.skip.net/DEC/spr-grpnam.txt). DEC. Retrieved February 6, 2022.

1. **[^](#cite_ref-193)** Bob Boyd (September 18, 1987). ["First Introduction of BACKUP utility"](https://groups.google.com/g/comp.os.vms/c/jcT66erFNek/m/0-cfcv9x1fEJ). [Newsgroup](/source/Usenet_newsgroup): [comp.os.vms](news:comp.os.vms). Retrieved February 6, 2022.

1. **[^](#cite_ref-194)** *VAX/VMS Release Notes Version 3.1*. DEC. August 1982. AA-N472A-TE.

1. **[^](#cite_ref-195)** *VAX/VMS Release Notes Version 3.2*. DEC. December 1982. AA-P763A-TE.

1. **[^](#cite_ref-196)** *VAX/VMS Release Notes Version 3.3*. DEC. April 1983. AA-P764A-TE.

1. **[^](#cite_ref-197)** *VAX/VMS Release Notes Version 3.4*. DEC. June 1983. AA-P765A-TE.

1. **[^](#cite_ref-198)** *VAX/VMS Release Notes Version 3.5*. DEC. November 1983. AA-P766A-TE.

1. **[^](#cite_ref-199)** *VAX/VMS Release Notes Version 3.6*. DEC. April 1984. AA-V332A-TE.

1. **[^](#cite_ref-200)** *VAX/VMS Release Notes Version 3.7*. DEC. August 1984. AA-CJ33A-TE.

1. **[^](#cite_ref-201)** [vms-source-listings](http://www.bitsavers.org/pdf/dec/vax/microfiche/vms-source-listings/AH-BT13A-SE__VAX-VMS_V4.0_SRC_LST_MCRF/AH-BT13A-SE__VAX-VMS_V4.0_SRC_LST_MCRF/)

1. **[^](#cite_ref-202)** [vms-source-listings](http://www.bitsavers.org/pdf/dec/vax/microfiche/vms-source-listings/AH-BT13A-SE__VAX-VMS_V4.0_SRC_LST_MCRF/AH-EF71A-SE__VAX-VMS_V4.1_SRC_LST_MCRF_UPD/)

1. **[^](#cite_ref-204)** ["Commitment to DII COE initiative provides longterm support and application portability for OpenVMS customers"](https://web.archive.org/web/20230907195317/https://h41379.www4.hpe.com/solutions/government/coe/). *[Hewlett Packard Enterprise](/source/Hewlett_Packard_Enterprise)*. Archived from [the original](https://h41379.www4.hpe.com/solutions/government/coe/) on September 7, 2023. Retrieved September 7, 2023.

1. **[^](#cite_ref-205)** ["HP OpenVMS Systems - OpenVMS Version 8.4"](https://web.archive.org/web/20100902030522/http://h71000.www7.hp.com/openvms84_announce.html). Archived from [the original](http://h71000.www7.hp.com/openvms84_announce.html) on September 2, 2010.

1. **[^](#cite_ref-206)** ["VMS Software, Inc. Launches New Version of OpenVMS Operating System Worldwide"](https://web.archive.org/web/20150807031302/http://vmssoftware.com/news/PR20150601/PR20150601_VSI_8.4-IHI.pdf) (PDF) (Press release). June 1, 2015. Archived from [the original](https://www.vmssoftware.com/news/PR20150601/PR20150601_VSI_8.4-IHI.pdf) (PDF) on August 7, 2015. Retrieved June 4, 2015.

1. **[^](#cite_ref-207)** ["VMS Software, Inc. Launches New Version 8.4-2L1 of OpenVMS Operating System Worldwide"](https://vmssoftware.com/about/news/2016-09-23-vms-software-inc-launches-new-version-8-4-2l1-of-openvms-operating-system-worldwide/). *VSI* (Press release). September 23, 2016. Retrieved May 4, 2021.

1. **[^](#cite_ref-208)** ["VMS Software, Inc. Launches VSI OpenVMS Alpha V8.4-2L1 for Alpha Hardware"](https://vmssoftware.com/about/news/2017-01-27-vms-software-inc-launches-vsi-openvms-alpha-v8-4-2l1-for-alpha-hardware/). *VSI* (Press release). January 27, 2017. Retrieved May 4, 2021.

1. ^ [***a***](#cite_ref-september-2020-update_209-0) [***b***](#cite_ref-september-2020-update_209-1) ["Roadmap Update"](https://web.archive.org/web/20200927075701/https://vmssoftware.com/products/roadmap/). *VSI*. September 2020. Archived from [the original](https://vmssoftware.com/products/roadmap/) on September 27, 2020. Retrieved September 23, 2020.

1. **[^](#cite_ref-210)** ["OpenVMS for x86 V9.0 EAK goes to first customer on May 15, 2020"](https://vmssoftware.com/about/news/2020-04-24-openvms-for-x86-eak-goes-to-first-customer-on-may-15-2020/). *VSI*. April 24, 2020. Retrieved May 4, 2021.

1. **[^](#cite_ref-vms9.2_211-0)** ["VSI OpenVMS v9.2 Released"](https://vmssoftware.com/about/news/2022-07-14-openvms-v92-for-x86-announced/). *VSI*. July 14, 2022. Retrieved July 14, 2022.

1. **[^](#cite_ref-vms9.2-1_212-0)** ["OpenVMS V9.2-1 Final Release"](https://vmssoftware.com/about/news/2023-06-15-openvms-v9-2-1-release/). *VSI*. June 15, 2023. Retrieved June 15, 2023.

1. **[^](#cite_ref-vms9.2-2_213-0)** ["OpenVMS V9.2-2 public availability"](https://vmssoftware.com/about/news/2024-01-25-openvms-v922-release-availability/). *VSI*. January 25, 2024. Retrieved January 25, 2024.

## Further reading

- Getting Started with OpenVMS, Michael D. Duffy, [ISBN](/source/ISBN_(identifier)) [1-55558-279-6](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-279-6)

- Introduction to OpenVMS, 5th Edition, Lesley Ogilvie Rice, [ISBN](/source/ISBN_(identifier)) [1-55558-194-3](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-194-3)

- Ruth Goldenberg; Saro Saravanan (1994). [*OpenVMS AXP Internals and Data Structures: Version 1.5*](https://books.google.com/books?id=sYYZAQAAIAAJ). Digital Press. [ISBN](/source/ISBN_(identifier)) [978-1555581206](https://en.wikipedia.org/wiki/Special:BookSources/978-1555581206).

- OpenVMS Alpha Internals and Data Structures: Memory Management, Ruth Goldenberg, [ISBN](/source/ISBN_(identifier)) [1-55558-159-5](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-159-5)

- OpenVMS Alpha Internals and Data Structures : Scheduling and Process Control : Version 7.0, Ruth Goldenberg, Saro Saravanan, Denise Dumas, [ISBN](/source/ISBN_(identifier)) [1-55558-156-0](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-156-0)

- VAX/VMS Internals and Data Structures: Version 5.2 ("IDSM"), Ruth Goldenberg, Saro Saravanan, Denise Dumas, [ISBN](/source/ISBN_(identifier)) [1-55558-059-9](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-059-9)

- Writing Real Programs in DCL, second edition, Stephen Hoffman, Paul Anagnostopoulos, [ISBN](/source/ISBN_(identifier)) [1-55558-191-9](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-191-9)

- Writing OpenVMS Alpha Device Drivers in C, Margie Sherlock, Leonard Szubowicz, [ISBN](/source/ISBN_(identifier)) [1-55558-133-1](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-133-1)

- OpenVMS Performance Management, Joginder Sethi, [ISBN](/source/ISBN_(identifier)) [1-55558-126-9](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-126-9)

- Getting Started with OpenVMS System Management, 2nd Edition, David Donald Miller, Stephen Hoffman, Lawrence Baldwin, [ISBN](/source/ISBN_(identifier)) [1-55558-243-5](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-243-5)

- The OpenVMS User's Guide, Second Edition, Patrick Holmay, [ISBN](/source/ISBN_(identifier)) [1-55558-203-6](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-203-6)

- Using DECwindows Motif for OpenVMS, Margie Sherlock, [ISBN](/source/ISBN_(identifier)) [1-55558-114-5](https://en.wikipedia.org/wiki/Special:BookSources/1-55558-114-5)

- Wayne Sewell (1992). [*Inside VMS: The System Manager's and System Programmer's Guide to VMS Internals*](https://books.google.com/books?id=c4UhAQAAIAAJ). Van Nostrand Reinhold. [ISBN](/source/ISBN_(identifier)) [0-442-00474-5](https://en.wikipedia.org/wiki/Special:BookSources/0-442-00474-5).

- The hitchhiker's guide to VMS : an unsupported-undocumented-can-go-away-at-any-time feature of VMS, Bruce Ellis, [ISBN](/source/ISBN_(identifier)) [1-878956-00-0](https://en.wikipedia.org/wiki/Special:BookSources/1-878956-00-0)

- Roland Hughes (December 2006). [*The Minimum You Need to Know to Be an OpenVMS Application Developer*](http://www.theminimumyouneedtoknow.com/app_book.html). Logikal Solutions. [ISBN](/source/ISBN_(identifier)) [978-0-9770866-0-3](https://en.wikipedia.org/wiki/Special:BookSources/978-0-9770866-0-3).

## External links

Wikimedia Commons has media related to [OpenVMS](https://commons.wikimedia.org/wiki/Category:OpenVMS).

- [VMS Software: Current Roadmap and Future Releases](https://vmssoftware.com/about/roadmap/)

- [VMS Software: Documentation](https://docs.vmssoftware.com/)

- [HP OpenVMS FAQ](https://web.archive.org/web/20200112171116/http://www.hoffmanlabs.org/vmsfaq/) at the [Wayback Machine](/source/Wayback_Machine) (archived January 12, 2020)

- [comp.os.vms Usenet group](news://comp.os.vms/), archives on [Google Groups](https://groups.google.com/group/comp.os.vms)

v t e Digital Equipment Corporation Key people Ken Olsen (founder and CEO, 1957–1992) Harlan Anderson (co-founder) Gordon Bell (VP of engineering) Robert Palmer (CEO, 1992–1998) Instruction set architectures, processors PDP-11 LSI-11 F-11 T-11 J-11 VAX V-11 MicroVAX 78032 CVAX SOC Rigel Mariah NVAX Alpha Alpha 21064 21066 21068 Alpha 21164 (21164PC) Alpha 21264 Alpha 21364 Alpha 21464 Other MicroPRISM StrongARM Computer terminals VT05 (1970) GT40 (1972) VT50/VT52 (1975) VT55 VT62 VT100 (1978) VT101 VT102 VT103 VT105 VT131 VT180 VT220 (1983) VT240 VT241 VT320 (1987) VT330 VT340 VT420 (1990) VT1000 (1990) VT510 (1993) VT520 (1994) VT525 Operating systems DECsys 4K DMS COS TOPS-10 RSX-15 TSS/8 OS/8 DOS-11 RT-11 RSTS/E RSX-11 IAS DSM-11 TOPS-20 VAX/VMS VAXELN ULTRIX Taos MICA OZIX Digital UNIX Programming languages BASIC-8 BASIC-PLUS BLISS DIBOL FOCAL MACRO-10 MACRO-11 MUMPS VAX MACRO DIGITAL Command Language Character sets Code page 1100 (Multinational) Code page 1287 (Greek) Code page 1288 (Turkish) Hebrew National Replacement RADIX 50 Special Graphics Technical Bus standards Digital Storage Systems Interconnect Massbus Q-Bus Standard Disk Interconnect Synchronous Backplane Interconnect TURBOchannel Unibus VAXBI Other hardware DECserver DECtalk DECtape DECwriter Digital Linear Tape Dynamically Redefined Character Set Firefly Flip-Chip module Gold key LK201 LK421 Mass Storage Control Protocol PALcode RA90 RK05 RL02 Star coupler System Module TU81 Related topics AdvFS AltaVista Compaq CPU Wars DECnet DECUS HP-Interex Digital Federal Credit Union Dynamic Debugging Technique FX!32 Local Area Transport Maintenance Operations Protocol On-line Debugging Tool PALcode Record Management Services ReGIS Sequence and Batch Language Sixel System Reference Manual Systems Research Center TD/SMP The Ultimate Entrepreneur VT640 WPS-8 Computers template Category Commons

v t e Compaq Acquired by Hewlett-Packard in 2002; existing product lines and intellectual property split between HP Inc. and Hewlett Packard Enterprise in 2015 Corporate aspects Founders Rod Canion Jim Harris Bill Murto Directors Michael Capellas Eckhard Pfeiffer Ben Rosen Acquisitions Thomas-Conrad (1995) NetWorth (1995) Microcom (1997) Tandem Computers (1997) Digital Equipment Corporation (1998) Zip2 (1999) Other topics Silicon Cowboys (2016 documentary) Hardware Servers SystemPro XL ProLiant* NonStop* AlphaServer* Workstations SystemPro ProSignia Professional Workstation AlphaStation* Desktops Business Deskpro 386 ProLinea Evo* HP Compaq** Elite** Pro** Consumer Presario* Portables and laptops Business Portable 1st generation Plus 286 II III 386 486 SLT LTE 1st generation Lite Elite 5000 series ProSignia Armada Evo* HP Compaq** Consumer Contura Presario* 1200 R3000** Internet appliances MSN Companion iPAQ desktop Handhelds and subnotebooks Concerto Contura Aero Aero C series tc1000 iPAQ handheld* tc1100** Architectures DEC Alpha* Software AltaVista OpenVMS TACL Tru64 UNIX Asterisk (*) denotes product lines continued after acquisition by HP Double asterisk (**) denotes product lines established after acquisition by HP DEC hardware video terminals DEC operating systems Hewlett-Packard

v t e Hewlett-Packard software Applications and utilities ALM† Application Security Center Business Service Automation Business Service Management Client Automation Software Cloud Service Automation Software CommonPoint† Enterprise Security Products† iconv Information Management Software† Integrity Virtual Machines IT Management Software Linux Imaging and Printing* mscape Network Management Center† Open Extensibility Platform OpenMail OpenView Storage Area Manager OpenText Quality Center† QuickTest Professional† Release Control Remote Graphics Software* Service Activator** Service Manager† Serviceguard SiteScope† Snapfish Lab Systems Insight Manager** Tesseract† TRIM† Visual User Environment WinRunner Database Enscribe** NonStop SQL** UCMDB† File systems and formats Hi Performance FileSystem** System Object Model** Veritas File System‡ Operating systems and environments Domain/OS HP-UX** HyperSpace HP LX System Manager MPE NewWave NonStop OS** OpenVMS† QuickPlay Rocky Mountain BASIC Time-Shared BASIC Tru64 UNIX webOS† Protocols and languages ePrint* HP-GL InkML PowerHouse‡ Printer Command Language Raster Transfer Language Printer Job Language Systems Programming Language Universal Print Driver* Asterisk (*) denotes software continued by HP Inc. Double asterisk (**) denotes software continued by Hewlett Packard Enterprise Dagger (†) denotes software divested and sold off Double dagger (‡) denotes third-party software

v t e Time-sharing operating systems Time-sharing system evolution BBN Time-Sharing System Berkeley Timesharing System Burroughs MCP CDC Kronos Compatible Time-Sharing System (CTSS) COS CP/CMS Cray Time Sharing System (CTSS) DTSS EMAS ITS LTSS MCTSS MTS Multics MUSIC/SP NLTSS NOS NOS/VE OpenVMS ORVYL and WYLBUR OS4000 Pick RAX RSTS/E TENEX TSO TSOS TOPS-10 TOPS-20 TSS TSS/8 Unix UTS VM VP/CSS VPS/VM VS/9 WAITS Category

v t e Operating systems General Comparison Forensic engineering History List Timeline Usage share User features comparison Variants Disk operating system Distributed operating system Embedded operating system Hobbyist operating system Just enough operating system Mobile operating system Network operating system Object-oriented operating system Real-time operating system Supercomputer operating system Kernel Architectures Exokernel Hybrid Microkernel Monolithic Multikernel vkernel Rump kernel Unikernel Components Device driver Loadable kernel module User space and kernel space Process management Concepts Computer multitasking (Cooperative, Preemptive) Context switch Interrupt IPC Process Process control block Real-time Thread Time-sharing Scheduling algorithms Fixed-priority preemptive Multilevel feedback queue Round-robin Shortest job next Memory management, resource protection Bus error General protection fault Memory paging Memory protection Protection ring Segmentation fault Virtual memory Storage access, file systems Boot loader Defragmentation Device file File attribute Inode Journal Partition Virtual file system Virtual tape library Supporting concepts API Computer network HAL Live CD Live USB Shell CLI User interface PXE

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Adapted from the Wikipedia article [OpenVMS](https://en.wikipedia.org/wiki/OpenVMS) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/OpenVMS?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.