You are welcome to criticise and make suggestions. Please, leave your comments in boxes like this one.

**Welcome!**

This is a wikion mathematics in parallel to the nLab. The site is just being constructed at the moment. In the long term, the wiki should be useful for research and education in mathematics insofar as the subject is treated with tools and notions of *category theory*. I keep changing my conception of the wiki but I presently think that it should present a full description of categorical mathematics, including proofs.

The **purpose of the Catlab** is to make polished expositions of mathematics to facilitate learning by students and researchers.

**New**: the theory of weak factorisation systems

**New**: the theory of factorisation systems

**New**: the theory of distributors

**New**: the natural model structure on $\mathbf{Cat}$

**New**: the theory of Quillen model structures

I will be working alone in the CatLab for a while, but I hope other people will join eventually. I may occasionally prove a new result or formulate a conjecture. I would like to give the Catlab an initial shape before letting it free. It could eventually function like a journal with an editorial board and contributors.

Revised on October 8, 2018 at 21:12:40
by
Richard Williamson