It's evolved from the merge of the two wide spread distributions - Whax and Auditor Security Collection. By joining forces and replacing these distributions, BackTrack has gained massive popularity and was voted in 2006 as the #1 Security Live Distribution by insecure.org. Security professionals as well as new comers are using BackTrack as their favorite toolset all over the globe.
BackTrack has a long history and was based on many different linux distributions until it is now based on a Slackware linux distribution and the corresponding live-CD scripts by Tomas M. (www.slax.org) . Every package, kernel configuration and script is optimized to be used by security penetration testers. Patches and automation have been added, applied or developed to provide a neat and ready-to-go environment.