“From the creators of BackTrack comes Kali Linux, the most advanced and versatile penetration testing distribution ever created.”
Kali Linux is a successor of BackTrack, an opensource linux distribution for security researchers.
The most obvious changes are Kali Linux is now based on Debian and a FHS-Compliant system.
In BackTrack, when you open a tool, it opens in a /pentest directory where almost all security tools are located and will not run if you just call it from any directory. In FHS-Compliant system, you do not have to go through /pentest directory but rather just call the tool from your terminal even you’re in a different directory tree.
Take a look at its current working directory of BackTrack and Kali Linux, that’s FHS-Compliant in Kali Linux.
Kali Linux can be downloaded in ISO, VMWare Images, and ARM Images. Download: http://docs.kali.org/downloading/download-official-kali-linux-images.
apt-get update && apt-get dist-upgrade
to upgrade to latest release of Kali Linux.