Kali Linux is an open source operating system designed from the ground up as a drop-in replacement for the well known BackTrack penetration testing Linux distribution. It includes more than 300 penetration testing tools, it's FHS compliant, supports a wide range of wireless devices, comes with a custom kernel patched for injection, supports multiple languages and it is completely customizable.
Availability and supported architectures
The distribution is available for download as standard and minimal ISO images, designed to support the 64-bit, 32-bit and ARMEL architectures, as well as custom VMware and ARM images that support the Raspberry Pi, BeagleBone Black, HP Chromebook, Samsung Chromebook, Samsung Galaxy Note 10.1, Cubieboard 2, CuBox, EfikaMX, Odroid U2, Odroid XU, Utilite Pro and SS808 devices.
The ISO images are Live CD/DVDs that allow the user to start the live environment with default options, in safe graphics mode, in forensic mode, using the simple or encrypted persistence mode, which allows you to save files on the USB stick and reuse it whenever you want, as well as to permanently install the operating system on a local drive.
GNOME Classic desktop environment for traditional hackers
Kali Linux's main and only desktop environment is powered by GNOME 3.4, which provides users with a traditional desktop environment that uses a two-panel layout and a pitch black theme. Default applications include the Iceweasel web browser, Empathy IM client, VLC Media Player, and Brasero CD/DVD burning tool.
Hundreds of penetration testing tools
As mentioned, the operating system includes over 300 penetration testing utilities, among which we can mention Aircrack-ng, Hydra, Nmap, Wireshark, Metasplot framework, Maltego, Owasp-Zap, SQLMap, John, Burpsuite, Johnny, Pyrit, SIPcrack, PWdump, Rainbowcrack, Maskgen, Hexinject, SSLSniff, and Dsniff.
In conclusion, those of you who are looking for an updated version of BackTrack should definitely download and use the Kali Linux operating system, as it is created by the same team of developers that started the world's most popular free penetration testing Linux distribution.