protected system by medusa
This is perfect software to protect your linux system.
Even it allows you to protect against inadvertent commands like 'rm -rf /' and so on. In case of hacking system medusa can protect itself, because it supports protection of processes against killing (generally send any signal to any proces) thus it remains only one way to disable medusa, to get to the console.
An open, cross-platform journaling program.
A scientific plotting package.