From Experimental Robotics
TinyOS is an event based operating environment designed for use with embedded networked sensors. More specifically, it is designed to support the concurrency intensive operations required by networked sensors with minimal hardware requirements. (From the TinyOS website).
The ZigBee motes made available to our group were produced by moteiv who have a Linux Install guide. They also provide support for Windows. BEFORE DOWNLOADING ANYTHING FROM SOURCEFORGE: Look at the age of the tarballs offered in the download section. If they are OLD, checkout the CVS instead. This will save you a great deal of pain and suffering!!!
If interfacing a mote with a PC, it is important that avr-binutils, avr-libc and avr-gcc be installed (or running 'make' in the $TOSROOT/tools/java directory will fail). NOTE that the versions needed are tinyOS specific, that is, the standard packages that came with your linux distro will not work. These tinyOS specific versions are available as RPM's or source (for source, when you run the configure script, use the correct options, they are mentioned in the source directory).
TinyOS allows the developer to write code that interacts with the numerous sensors (light sensors, accelerometers etc) on a mote through the nesC programming language.
Generally the best place to go for support is to sign up on the TinyOS mailing list. Before you post a question be sure to check the TinyOS tutorials on the TinyOS website and also search the mailing list archive in the support section of the TOS website.