Kerberos was developed as the authentication engine for MIT’s Project Athena in 1983. Released as Open Source in 1987, it became an IETF standard in 1993.
Massachusetts Institute of Technology

Documentation

Kerberos was originally developed for MIT's Project Athena in the 1980s and has grown to become the most widely deployed system for authentication and authorization in modern computer networks. Kerberos is currently shipped with all major computer operating systems and is uniquely positioned to become a universal solution to the distributed authentication and authorization problem of permitting universal "single sign-on" within and between federated enterprises and peer-to-peer communities. MIT has developed and maintains implementations of Kerberos software for the Apple Macintosh, Windows and Unix operating systems.

The current version of the Kerberos Software Documentation.

Read documents published by the MIT KIT Consortium: Publications

A guided tour of Kerberos: Tutorial

Links to additional Kerberos documentation resources: Useful Links