The Linutop OS offers a security system bound to its internal architecture. It uses the concept of LiveCD, but makes it more flexible.
The system is contained in a single file that can't be modified. No matter what happens on the system, you'll always be able to restore the original state of the system using this file.
By default the Linutop OS behaves like any system. Anything you do is written on disk and will still be there after a reboot. Administration tasks will require a master password.
Switching the system in Lock mode will make all new changes temporary. After having configured the system to your needs, switching to this mode will allow to discard all new changes on reboot. You'll always find the same start at startup.