Hi, I'm pleased to announce that BeRTOS 2.6 (www.bertos.org) now supports the Arduino Mega board.
Other supported drivers for AVR ATmega CPUs are: - ADC - UART - FLASH - I2C - PWM - SPI
Real world projects are included with source distribution.
For more information, check the official announcement on BeRTOS blog (http://www.bertos.org/blog/embedded/bertos-26-available).
BeRTOS is a real time operating system (RTOS) suitable for embedded platforms. It runs on many microprocessors and microcontrollers, ranging from 8-bit to 32-bit CPUs and even PCs.