FreeRADIUS is the premiere open source RADIUS server. Based on current
statistics, there are over 50,000 deployments of the software. These
deployments include small sites with 10 users, large-scale enterprises with
tens of thousands of users, and carrier-class deployments with over 10 million
users. In total, the sites that we know are using FreeRADIUS support nearly
100 million users. The only other servers that come close in terms of market
share and/or number of sites are ACS and IAS.

The server scales easily from embedded systems with small amounts of memory to
systems with millions of users. It is fast, flexible, configurable, and
supports more authentication protocols than most commercial servers. It
includes support for SQL, LDAP, RADIUS Proxying, failover, load balancing, and
nearly 100 vendor dictionary files. It can perform authentications via the
PAP, CHAP, MS-CHAP, EAP-MD5, EAP-GTC, EAP-TLS, EAP-TTLS, PEAPv0, LEAP,
EAP-SIM, and Digest authentication protocols. It has reached a stable 1.1
version, with incremental improvements added in each release.

The server is released under the GNU General Public License (GPL), which means
that it is free to download and install.


WWW: http://www.freeradius.org/
