Experience with ChibiOS RTOS?

I have been doing some research on RTOS just to see what they could do. I found a forum topic where someone had ported ChibiOS and integrated it with Arduino IDE. Would it be possible to setup up ChibiOS without the IDE and just use it standalone on the atmega328p and use only the features inherent to the OS itself?

Would it be possible to setup up ChibiOS without the IDE and just use it standalone on the atmega328p and use only the features inherent to the OS itself?

Yes, it would be. There is the avr port in original chibios repo available. You have to care about your compiler/linker and system setup, i/o, etc. then.
http://forum.chibios.org/phpbb/viewforum.php?f=21