Open source Contiki is an operating system for embedded smart objects and version 2.4 came out today.
The H reports that the new version of Contiki includes new experimental platforms and improved stability.
"The BSD licensed operating system is designed to be small, highly portable and work in networked, but memory constrained systems, such as sensor network nodes." According to The H, "Typical configurations can use as little as 2KB of RAM and 40KB of ROM and Contiki has been ported to computers such as the Commodore 64 and microcontrollers such as the TI MSP430 and Atemel AVR."
Two experimental platform, Crossbow MicaZ and the Sensinode CC2430/8051 were added to this version of Contiki, as well as a new sensor API, reworked wireless MAC protocols, improved power efficiency and the handling of collision and interference, The H reported.