The Computers: Software: Operating Systems: Realtime: (FreeRTOS Realtime )

FreeRTOS is a realtime operating system (RTOS) for embedded devices. Ported to many processors (ARM 7, Cortex-M3; AVR (MegaAVR); ColdFire; HCS12, H8S; MicroBlaze; MSP430; PIC 18, 24, dsPIC; RDC, Renesas H8-S; x86; 8051, 8052), and ported to new ones often. It was the first realtime kernel available for production CORTEX-M3 processors. The FreeRTOS scheduler is small, simple, and can be configured for preemptive or cooperative operation. The kernel is made of only 3 or 4 C files, depending on whether coroutines are used or not. From Version 4, FreeRTOS lets programs use coroutines, and tasks. Coroutine are lightweight tasks that use little memory. To make source code readable, portable, and maintainable, it is done mostly in C, with a few assembler functions where vital. FreeRTOS Realtime Operating Systems Software Computers.

FreeRTOS is a popular real-time operating system kernel for embedded devices, that has been ported to 35 microcontrollers. (wikipedia)