rivet is hosted by Hepforge, IPPP Durham
The Rivet MC analysis system  2.6.1
The Rivet validation framework

Rivet is principally a C++ framework for Monte Carlo event generator validation. It is built on the dual concepts of analyses - routines which implement published experiment analyses - and projections - routines which extract observables from event records. Rivet is designed to be efficient, via automatic caching of projection results for each event.

For more information on Rivet, please see the wiki documentation, managed at http://projects.hepforge.org/rivet/trac/wiki .