uC/OS-II, The Real-Time Kernel is a highly portable, ROMable, very scalable, preemptive real-time, multitasking kernel (RTOS) for microprocessors and microcontrollers. uC/OS-II can manage up to 63 application tasks.  
     
  uC/OS-II License: http://www.ucos-ii.com/contents/products/ucos-ii/licensing.html  
     
  uC/OS-II Ports: http://www.ucos-ii.com/contents/products/ucos-ii/ports-misc.html  
     
 
(uC/OS-II port of this project can also be found there,
as it has been accepted by the uC/OS-II official site.
)