You will find the documentation here : http://pyfreebilling.readthedocs.org/en/latest/index.html
It will update as new functionnalities will be added or new version released.
PyFreeBilling is a open source wholesale billing application based on Freeswitch.
I recently decided to migrate the PyFreeBilling project (wholesale softwitch based on freeswitch) from Github to Bitbucket. The new address is https://bitbucket.org/mwolff/pyfreebilling
Why ? because i like BitBucket and overall the tools for managing issues. I used extensively for my other projects.