Lejos OSEK

Lejos OSEK is an open source firmware for LEGO Mindstorms NXT consisting of LEJOS NXJ platform source code and the TOPPERS OSEK kernel source code, and glue code to make them work together.

• ANSI C/C++ programming environment by using GCC (GNU-ARM) tool chain
  
• LEJOS NXJ platform based device API for NXT Sensors, Motors, and other devices
  
• TOPPERS OSEK provided real-time multi tasking features proven in automotive industry
  
• Rate Monotonic Scheduling with 1msec resolution by using OSEK Alarm
  
• Several examples (include a NXTway)
  
• Fast execution and less memory consumption, an application may consume totally just about 20k bytes (includes LEJOS OSEK itself).
  

Also, Embedded Coder Robot NXT Demo.