Real-time operating system for ARM cortex m0-7, only the most necessary. Type OS - preemptive multitasking, with dynamic allocation of operating time. Short stack support for math-free tasks. Free use of interrupts without external control, and blocking processes. A set of functions for task management, real-time timers, work with external and internal resources, messaging. Opportunities for external monitoring of the state of active tasks - without stopping the ARM core (built-in). Ability to observe live variables (requires a fast communication interface). The ability to change part of the OS algorithms, without losing the overall functionality.