| A Gentle Introduction to Category Theory: Lecture notes by Maarten M. Fokkinga introducing some important notions from category theory, in particular adjunctions. Proofs are given in a calculational style, and the (few) examples are taken from algorithmics. The text is a long PostScript file. |
| Categorical Myths and Legends: An archive of stories about category theorists. |
| Categories Home Page: Web page for the category theory mailing list. |
| Categories, Quantization, and Much More: Introductory article by John Baez. |
| Category Theory: This expository article is an entry in the Stanford Encyclopedia of Philosophy. |
| Category Theory and Homological Algebra: In the "known maths" series. |
| Computational Category Theory: An implementation of concepts and constructions from category theory in the functional programming language Standard ML. Documentation and code. |
| CT Category Theory: Section of the e-print arXiv dealing with category theory, including such topics as: enriched categories, topoi, abelian categories, monoidal categories, homological algebra. |
| Descent and Category Theory Connections: Maintained by M. Alsani. |
| Groupoid Home Page: Maintained by Birant Ramazan. Address book, open problems, meetings, pictures, other resources. |
| Groupoids: Notes by Ronald Brown. |
| Higher-Dimensional Categories: An illustrated guide book by Eugenia Cheng and Aaron Lauda (PS/PDF). |
| Open Problems on Model Categories: Problems on model categories listed by Mark Hovey at Wesleyan University. |
| Paul Taylor's Home Page: Includes papers on category theory. |
| Structures Directory: Email directory of logicians, algebraists, and programming linguists working primarily on structural problems in mathematics and computer science. |
| Toposes, Triples and Theories: By Michael Barr and Charles Wells, 1983. A revised and corrected version is now available free for downloading. Formats: DVI, PDF, PostScript. |
Classical
