FreeRADIUS is a high-performance, open-source RADIUS server widely used for network authentication, authorization, and accounting (AAA). Originally released in 1999, FreeRADIUS supports a broad range of authentication protocols and is highly extensible through modules and integrations with databases like MySQL, LDAP, and Active Directory.

Features of FreeRADIUS:

• Supports various authentication methods including PAP, CHAP, MS-CHAP, and EAP.
• Scalable and flexible, suitable for small networks to large-scale enterprise deployments.
• Modular architecture with support for MySQL, LDAP, PostgreSQL, and more.
• Extensive logging, debugging, and policy enforcement capabilities.

To check the version of FreeRADIUS installed, run:

freeradius -v

Disclaimer: FreeRADIUS is released under the GNU General Public License. It is a community-driven project, and users are encouraged to consult the official documentation and contribute to its development.