SMRadius is a high performance pre-forked radius AAA server, it features a highly configurable backend engine supporting flexible data specifications. The primary goal of the SMRadius project is to provide an extremely flexible authentication platform which may serve a large number of industries (ISPs, WiSPs ... etc).
SMRadius is an open source project, FREE to download, FREE to use, FREE to extend. Actively maintained and improved. A full support structure including IRC channel for near 24 hour Support.