Kali Linux (Kali) is a Linux distribution system that was developed with a focus on the penetration testing task. Previously, Kali Linux was known as BackTrack, which itself is a merger between three different live Linux penetration testing distributions: IWHAX, WHOPPIX, and Auditor.
BackTrack is one of the most famous Linux distribution systems, as can be proven by the number of downloads that reached more than four million as of BackTrack Linux 4.0 pre final.
Kali Linux Version 1.0 was released on March 12, 2013. Five days later, Version 1.0.1 was released, which fixed the USB keyboard issue. In those five days, Kali has been downloaded more than 90,000 times.
The following are the major features of Kali Linux ( http://docs.kali.org/introduction/what-is-kali-linux ):
• It is based on the Debian Linux distribution
• It has more than 300 penetration testing applications
• It has vast wireless card support
• It has a custom kernel patched for packet injection
• All Kali software packages are GPG signed by each developer
• Users can customize Kali Linux to suit their needs
• It supports ARM-based systems