ARTX is a pre-emptive real-time operating system kernel for Atmel's 8-bit AVR microcontrollers.
Its primary goal is a small memory footprint. The minimal configuration uses only 420 bytes of flash memory. Various optional components can be configured at compile time, increasing both functionality and code size.
There is support for EEPROM access, serial and SPI communication, as well as experimental 1-wire bus code. The kernel supports an arbitrary number of tasks with different intervals, priorities and stack sizes. There are weird features like synchronization of a kernel tick with an external time source.
It is also possible to build ARTX with support for monitoring, in which case it'll occupy a serial port to send out monitoring packets that can be displayed using a small GUI to determine information like live task load and stack usage.
ARTX is the abbreviation for Atmel/AVR Real Time eXecutive.
Please have a look at the source code for more documentation. You can run
make dox
to generate the documentation from the embedded doxygen comments.