As a catalog of mathematical objects, it should be comparable to Metamath: http://de.metamath.org/index.html http://de.metamath.org/index.html But this project

As a catalog of mathematical objects, it should be comparable to Metamath: http://de.metamath.org/index.html http://de.metamath.org/index.html But this project seems to be specific to number theory, and not really concerned with proofs at all. Where can I find the webcast mentioned?