Our website provided a free download of RDXServer X 1.1 for Mac. The program relates to System Tools. This software for Mac OS X is a product of Athena Online.
From the developer:
RDXServer is a cross-platform Radius Server, supporting standard Radius Access, Authorisation and Accounting Services. Built under MacOSX with stability, performance, and flexibility in mind, RDXServer handles all remote access authentications scaling from small wireless networks up to large ISP's.
You may want to check out more software for Mac, such as InsomniaT, which might be similar to RDXServer X.