Kali is by far the most well known and widely adopted penetration testing framework, but another contender is gaining popularity. Parrot Security is a Debian based Testing pentest framework developed by Lorenzo Faletra in 2013. The tool runs on Mate Desktop, has its own secure sandbox environment, as well as its own applications repository.
The interface is aesthetically pleasing and quite intuitive. Windows applications can be run through Win. The team of developers is international in scope, and updates are quite frequent.
If you're interested in looking at it, the Parrot website is at https://www.parrotsec.org/.
