MicroC-OS

Application Note µC/OS-II and Turbo C++ 1.01
Describes port of µC/OS-II to x86 CPU, via Borland compiler. Quantum Leaps, LLC. [PDF]
http://www.quantum-leaps.com/doc/AN_uCOS-II_tcpp101.pdf

Micrium, Inc.
Makes µC/OS, µC/OS-II (MicroC/OS, MicroC/OS-II), full source code, no royalty, free non-commercial use; other software for embedded use: Embedded Systems Building Blocks, µC/GUI for most 8- to 64-bit processors, µC/FS FAT filesystem.
http://www.micrium.com/

MicroC/OS-II
Growing article, with links to many related topics. Wikipedia.
http://en.wikipedia.org/wiki/MicroC/OS-II