A collection of machine-checkend mathematical proofs
The Archive of Formal Proofs is a collection of proof libraries, examples, and larger scientifc developments, mechanically checked in the theorem prover Isabelle. It is organized in the way of a scientific journal. Submissions are refereed.
A set of MediaWiki extensions and other tools developed for the Twelf wiki (http://twelf.plparty.org) that enable a wiki to naturally incorporate logic Twelf in a number of meaningful and useful ways.