XtRadius is a freeware radius server implementation.

The main difference between XTRadius and other radius servers, is that it 
allows you to execute fully customisable scripts to handle authentication 
and user accounting. A benefit of this feature is that instead of using 
either the radius users file, or the system password file for 
authentication, you can call a script/application which may query any 
source (such as an SQL database), and check for valid conditions before 
allowing a user to login. Unlike other solutions, no patching is required.

The latest release of XTRadius is based on Cistron Radius 1.6.4, and 
includes all the features of Cistron, as well as other improvements.

The XTRadius homepage is located at:

	http://www.xtradius.com/

Cryptographic signatures and checksums may be provided by
the developers at the URL(s) above.  Wiretapped recommends
that users check these before use of the software/information.