One of the nice things about SourceForge are the hosted applications it provides to enable:-
to be made in a systematic and traceable way using a tracker tool. A description of the trac tool is provided by SourceForge.
Sourceforge also provides an overview of the support available for the UML profile for TRAK project.
In addition there are discussion forums for posting and responding to topics raised
There is a wiki on the trak project site on Sourceforge.
There is a more general wiki for the TRAK community that covers TRAK-related topics and more general modelling including the application of views, organisation of models etc.
The ways in which you could help - if you've the inclination to are covered on the Open Source page. You don't need to be a brainiac or a large organisation to help make a difference!