TinyOS is an operating system designed for tiny, low-power wireless sensors. It runs on Atmega and Texas Instruments microcontrollers as well as ARM Cortex M3 processors and has extensive support for wireless networking. TinyOS began as a research project at UC Berkeley and is now developed and maintained by a worldwide group of open source developers.
Sirikata is a BSD-licensed open source platform for virtual worlds. It provides servers that simulate the world and distribute content, a graphical client, and scripting language support, allowing you to focus on creating the objects and behaviors unique to your world.