Saw this on the AVRfreaks site:
Arduino-Lite is a lightweight high-performance firmware library for AVR MCUs, which is developed based on the original Arduino project. Robopeak make it easy to use, just like the Arduino. Compared to the original library, Arduino-Lite generates smaller binaries and perform faster.
And now, we are honored to introduce the Arduino-Lite to the public, and to make it open source.There are three articles about it. It's too much to post them here. If you are interested in Arduino-Lite, please read the articles by clicking the URL below.
Possible substitute for those hating the Arduino IDE?
http://www.elecfreaks.com/92.html
http://www.elecfreaks.com/167.html
Lefty