See also:

• Games: Card Games: Special Decks: Ccard  (1)
• Science: Math: Logic and Foundations  (831)
• Science: Math: Topology: Algebraic Topology  (29)

• 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.
• 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.
• 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.
• 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.