Here is the code along with some documentation for b-matching. The code is in C, but I include a MATLAB version and a MATLAB interface for the C version. I also include pre-compiled Windows, Linux, and Mac OS X binaries.
Send me email if you have any questions. My email address is on my homepage.
Here is some new code to do bd-matching with different degree constraints on each node. New features include user set parameters for maximum iterations, damping. The new code operates on full graphs so it can be used as an approximation for bd-matching on unipartite graph. See the README for more info.