MultiTOS
(MTOS) A new version of TOS. MultiTOS's main advantage was support for pre-emptive multitasking and memory protection. It also supported the latest (and far superior) versions of GEM. MultiTOS was supplied with the Falcon030 range of computers from Atari.
It is a little known fact that the MultiTOS kernel was based heavily on the freeware OS MinT which was developed long before Atari got MultiTOS working.