TIPC is a LAN protocol, originally designed by Jon Maloy at Ericsson. Its purpose is to provide an efficient, transparent, and scalable communication mechanism for a wide range of possible cluster configurations. It has been in the linux kernel since 2.6.16.
http://tipc.sf.net  is the main TIPC site.
The TIPC community is just starting to use this wiki, so there isn't much content here yet.
Please feel free to contribute once you have an account here: http://linux-net.osdl.org/index.php?title=Special:Userlogin&returnto=Main_Page 
Here's the TIPC FAQ 
TIPC is under active development. Some of the features that need to be worked on include:
- Multiclustering will enable TIPC clusters to scale beyond a LAN and/or to a larger number of nodes. Jon Maloy has an initial implementation and Allan Stephens is now working on this feature.
- Secondary nodes will enable TIPC to scale down to smaller general purpose CPUs and DSPs. Some initial design ideas have been worked out but no one is working on this yet.
- Performance degraded during the process of including TIPC in the standard kernel. There are a lot of ideas around for how this could be improved again, and work on this is planned towards the end of 2006.