BackTrack is a Linux-based penetration testing arsenal that aids security
professionals in the ability to perform assessments in a purely native
environment dedicated to hacking.
Regardless if your making BackTrack your primary operating system, booting
from a LiveDVD, or using your favorite thumbdrive, BackTrack has been customized
down to every package, kernel configuration, script and patch solely for the
purpose of the penetration tester.
BackTrack 4 (codenamed “pwnsauce”) includes a new kernel, a larger and
expanded toolset repository, custom tools that you can only find on BackTrack,
and more importantly, fixes to most major bugs that we knew of.