"There are basically two established Linux distributions with a
serious bent on security, ImmunixOS and NSA's SELinux. They both
have released working, mature code that you can get ahold of and
use. There are possibly other projects, but to the best of my
knowledge none are shipping code right now."
"The NSA's SELinux is extremely powerful as far as configuring
security to a very granular level goes. However, for most people
and applications, this level of security is overkill (and there are
some significant performance hits as well)."
"ImmunixOS is aimed at making Linux more robust and improving
its survivability in the face of new security flaws. ImmunixOS also
has a much gentler learning curve than the NSA's SELinux, and
addresses issues that NSA SELinux does not."
