FOM - A closed, moderated, e-mail list for discussing Foundations of Mathematics moderated by Martin Davis. Archive available.
Foundations of Mathematics - Reviews the foundations of mathematics with reference materials structured as content pages of a book. Includes links to expository materials.
Hilbert II - Mathematical Foundation Project - The Goal of Hilbert II, which is in the tradition of Hilbert's program, is the creation of a system that enables a working mathematician to put theorems and proofs (in the formal language of predicate calculus) into it.
Mizar Project - An attempt to reconstruct mathematical vernacular into a formal language which can be read by humans and also verified by software.
Practical Foundations of Mathematics - Online text of the book by Paul Taylor, together with supporting materials. The text aims to provide a conceptual and formal foundation for mathematics and computer science.
QED Project - Build a single, distributed, computerized repository that rigorously represents all important, established mathematical knowledge
