M2OS is a small Real-Time Operating System that allows running multitasking applications in small microcontrollers with scarce memory resources.
M2OS implements a simple scheduling policy based on non-preemptive one-shot tasks which requires a very small memory footprint. Moreover, with this scheduling policy the same stack area can be used by all the tasks and, consequently, the system only needs to allocate a stack area large enough to fit the largest task stack.
It’s quite rare we find an operating system that’s actually never been mentioned on ONSews before. To be fair, it’s only been around since March of this year and it’s highly niche, but still.