Gentoo overlay for security tools as well as the heart of the Pentoo Livecd
Pentoo is a Live CD and Live USB designed for penetration testing and security assessment. Based on Gentoo Linux, Pentoo is provided both as 32 and 64 bit installable livecd. Pentoo is also available as an overlay for an existing Gentoo installation. It features packet injection patched wifi drivers, GPGPU cracking software, and lots of tools for penetration testing and security assessment. The Pentoo kernel includes grsecurity and PAX hardening and extra patches - with binaries compiled from a hardened toolchain with the latest nightly versions of some tools available.
It's basically a Gentoo, a Linux-based operating system and a meta-distribution, which means that it is built automatically from source code and is customized with the functionality that you want to have and without the unnecessary features that you want to avoid, with lots of customized tools, customized kernel, and much more...