Xtreme Liteos 8.1 Link 【Popular — 2024】

Version 8.1 introduces the a hybrid time-triggered and event-driven scheduler that scales from one to 256 tasks with O(1) complexity. Unlike the fixed-priority preemptive schedulers of older RTOSes, the Fractal Scheduler uses a bitmap of hierarchical run queues, allowing context switches in as few as 9 cycles on a 32-bit ARM Cortex-M0+ core.

These builds are unofficial. Because they are created by individuals (like those hosted on Internet Archive xtreme liteos 8.1