Rmetrics Open Source Softwareis an R-forge based project founded in March 2008 that provides 44 R packages implemented by a team of 22 developers worldwide. Most of the available packages are part of R’s CRAN project. To get an idea about the size and quality of this Open Source project you should take a look on the Ohloh software evaluation page. There you can get an overview about the software development including code analysis, estimated value and manpower, people behind the project, and its community.
The development page can be found on r-force.