Portable, mini realtime scheduler (RTOS kernel); how to make full embedded solutions on Windows host with quality open source tools, low cost hardware; supports ARM7, PIC18, 8051, Atmel(Mega)AVR, RDC8822 (AMD AM186 clone), PC with DOS. [Open Source, GPL]
Growing article, with links to many related topics. Wikipedia.
FreeRTOS Real Time Kernel
Project page: news, forums, support, CVS, bug reports, feature requests, statistics. SourceForge.
Porting and Using Newlib in Embedded Systems
Introduces newlib's most important features, shows how to use newlib in a GNU-based embedded system, and describes in detail how to port newlib to a runtime environment featuring the uC/OS realtime operating system.
Wittenstein High Integrity Systems
High integrity engineering design, development, production; focus: software, safety critical engineering of software and systems; makes and supports FreeRTOS variants SafeRTOS, FreeRTOS-pro. Bristol, UK.