freeDiameter is a implementation of the Diameter protocol specified
in RFC3588. Diameter is a protocol for carrying Authentication,
Authorization and Accounting information. It is an evolution of
the widely-deployed RADIUS protocol. freeDiameter also implements
the changes to the Diameter protocol introduced by the rfc3588bis
Internet Draft (work in progress).

freeDiameter is open-source and released under a BSD compatible
license. It is mainly written in the C language, which provides
excellent performance and small memory footprint.

Homepage:
http://www.freediameter.net/trac/
