The Categories mailing list is a mailing list on the topic of category theory.
The list commenced in 1990. From 1990 to 2023, the mailing list was hosted by Mount Allison University (categories@mta.ca) and moderated by Bob Rosebrugh. In 2023, the mailing list was transitioned to Macquarie University (categories@mq.edu.au) and is currently moderated by Jean-Simon Lemay.
The journal Theory and Applications of Categories was launched on the mailing list in January 1995.
The list’s messages are archived in a number of different ways, depending on date:
For June 1994 to November 1999, there is a curated website, organised alphabetically by topic/title: https://www.mta.ca/~cat-dist/catlist/
For 11 March 1990 (the start) to July 2009 (when a change in Outlook led to a halt in archiving), there are compiled monthly digests, organised in yearly/monthly folders here: https://www.mta.ca/~cat-dist/archive/
An dump of the Gmane archive (otherwise only accessible via the protocol nntp) can be found on GitHub, which is searchable, but not sorted or archived in any particularly human-readable way.
To subscribe, please email js.lemay@mq.edu.au or categories-admin@mq.edu.au with the word ‘subscribe’.
To unsubscribe, please email js.lemay@mq.edu.au or categories-admin@mq.edu.au with the word ‘unsubscribe’.
The website for the old categories mailing list (categories@mta.ca):
Last revised on March 27, 2025 at 08:05:20. See the history of this page for a list of all contributions to it.