The Femto OS is a very concise portable real time – preemptive operating system (RTOS) for embedded microcontrollers with minimal ram and flash, say 2KB .. 16KB flash and 128 .. 1024 bytes ram. The main target is the Atmel AVR architecture, such as the ATtiny or smaller ATmega series.
Femto OS – RTOS for Atmel AVR ATmega
Femto OS is specially made for small embedded devices. For example, the ‘Smallest application’ is the application called ‘Bare’ compiled for the ATmega8. It solely runs a 16 bit led counter on the idle task hook. It consumes 258 bytes of flash and 10 bytes of ram.
– Ruud Vlaming