Security Enhanced Linux (SELinux) is a security enhancement to Linux implementing mandatory access control (MAC).
Users and processes can be granted their least required privileges in a much more granular way than with traditional Unix access control.
For example, you can define a policy to prevent your web browser from reading your SSH keys.
The security model of SELinux has been ported to other operating systems; see SEBSD for FreeBSD and Project fmac for OpenSolaris.
NodeZero was formally known as Ubuntu Pentest Edition and was the 1st Ubuntu/Gnome based pentesting distro that was released.
[Note]: SELinux isn’t a distribution by itself but a security enhancement to Linux that can be enabled by your distribution or vendor (or yourself if you are very motivated)