{{short description|Wiki for mathematics, physics, and philosophy}} {{DISPLAYTITLE:''n''Lab}}{{Infobox website | name = nLab | founded = November 28, 2008 | creator = Urs Schreiber | url = {{URL|https://ncatlab.org/}} | programming_language = Ruby, Python<ref>{{Citation |title=ncatlab/nlab |date=2025-09-20 |url=https://github.com/ncatlab/nlab |access-date=2025-10-06 |publisher=nLab}}</ref> }}
The '''''n''Lab''' is a wiki for research-level notes, expositions and collaborative work. It includes original research in mathematics, physics, and philosophy with a focus on methods from type theory, category theory, and homotopy theory. The ''n''Lab espouses the "''n''-point of view"<ref>[https://ncatlab.org/nlab/show/nPOV ''n''POV] in ''n''Lab</ref> (a deliberate pun on Wikipedia's "neutral point of view"), which is that type theory, homotopy theory, category theory, and higher category theory provide a useful, unifying viewpoint for mathematics, physics and philosophy.
The ''n'' in ''n''-point of view could refer to either ''n''-categories as found in higher category theory, ''n''-groupoids as found in both homotopy theory and higher category theory, or ''n''-types as found in homotopy type theory.
==Overview== The ''n''Lab was originally conceived to provide a repository for ideas (and even new research) generated in the comments on posts at the ''n''-Category Café, a group blog run at the time by John C. Baez, David Corfield and Urs Schreiber. Eventually the ''n''Lab developed into an independent project, which has since grown to include whole research projects and encyclopedic material.<ref name="What_is_the_nLab">Urs Schreiber, [https://ncatlab.org/schreiber/show/What+is...+the+nLab What is... the nLab?] </ref>
Associated with the ''n''Lab is the nForum: an online discussion forum for announcement and discussion of ''n''Lab edits (the analog of Wikipedia's "talk" pages) as well as for general discussion of the topics covered in the ''n''Lab. The preferred way of contacting the ''n''Lab steering committee is to post on the nForum.<ref name="nLab_contact_steering_committee">[https://ncatlab.org/nlabmeta/show/steering+committee Steering committee] in ''n''Lab meta</ref> An experimental sub-project of the ''n''Lab is the '<nowiki/>''Publications of the ''n''Lab''', intended as a journal for refereed research articles that are published online and cross-hyperlinked with the main wiki. This sub-project appears to be inactive as of 2014.<ref>{{Cite web |title=Publications |url=https://ncatlab.org/publications/published/ |access-date=2023-10-27 |website=ncatlab.org}}</ref>
The ''n''Lab was set up on November 28, 2008 by Urs Schreiber using the Instiki software provided and maintained by Jacques Distler. Since May 2015 it runs on a server at Carnegie Mellon University that is funded in the context of Steve Awodey's Homotopy Type Theory MURI grant.<ref>{{cite web |last1=Awodey |first1=Steve |title=HoTT awarded a MURI |url=https://homotopytypetheory.org/2014/04/29/hott-awarded-a-muri/ |website=Homotopy Type Theory |access-date=8 August 2020 |date=29 April 2014}}</ref> The domain ncatlab.org is owned by Urs Schreiber.
The ''n''Lab is listed on MathOverflow as a standard online mathematics reference to check before asking questions.<ref name="MO_howtoask">[https://web.archive.org/web/20130606040144/http://mathoverflow.net/howtoask#homework MathOverflow], 1.0 'How to ask' page. Archived on 2013-06-04.</ref> Many questions and answers link to the ''n''Lab for background material.<ref name="MO_nlab_mentions">[https://mathoverflow.net/search?q=nlab MathOverflow], Results for a search for 'nlab'. As of 2018-12-11 there are over 800 results.</ref> It is one of two wikis mentioned by the mathematical physicist John C. Baez in his review of math blogs for the American Mathematical Society.<ref>John C. Baez, "[https://www.ams.org/notices/201003/rtx100300333p.pdf Math Blogs]", ''Notices of the American Mathematical Society'', March 2010</ref>
There is an informal steering committee, which doesn't run the ''n''Lab,<ref>[https://ncatlab.org/nlabmeta/show/steering+committee Steering committee] in ''n''Lab meta</ref> but exists in order to resolve issues that could cause the whole project to run into trouble.
The content of this wiki is not placed under a specific copyright license.<ref>{{Cite web |title=nLab |url=https://ncatlab.org/nlab/show/HomePage#TermsOfUse |access-date=2023-10-28 |website=ncatlab.org}}</ref>
==See also== {{Portal|Mathematics}} *MathOverflow
== References == <references />
== External links == * [https://ncatlab.org/nlab/show/HomePage ''n''Lab] * [https://nforum.ncatlab.org/ nForum] * [https://ncatlab.org/publications/published/HomePage Publications of the ''n''Lab]
Category:Mathematics websites Category:Wikis