As announced previously, we've now moved our source code to GitHub!
We were able to import the trunk of the subversion repository without any loss to our new git repository on GitHub.
Visit MATSim on GitHub: https://github.com/matsim-org/matsim
To clone the MATSim source code, use https://github.com/matsim-org/matsim.git as URI.
To set up Eclipse, have a look at the updated documentation: Using Eclipse for MATSim development.