BackTrack is a Linux distribution distributed as a Live CD which resulted from the merger of WHAX and the Auditor Security Collection, which is used for Penetration testing. It allows the user to include customizable scripts, additional tools and configurable kernels in personalized distributions. The BackTrack project was created by Mati Aharoni and Max Moser and is a collaborative effort involving the community.

BackTrack 2 was released on March 6, 2007 and includes over 300 security tools. A beta version of BackTrack 3 was released on December 14, 2007, but it was announced that its main focus was to support more and newer hardware as well as provide more flexibility and modularity.

BackTrack 3 was released on June 19, 2008. New additions include SAINT and Maltego. Nessus was not included in this release, and the developers decided not to upgrade from kernel version 2.6.21.5.

BackTrack 4 Beta was released on February 11, 2009, with the biggest change being the move to a Debian-based distribution.