EMF Views is an Eclipse plugin that brings the concept of database views to the modeling world
Constellation organizes and manages collaborative (distributed) World Wide Modeling projects,
Moka extensions provides a number of plugins that extend the functionality of Papyrus Moka engine for fUML simulation:
NeoEMF is a project that aims at handling large EMF models in an efficient and scalable way.
Papyrus extensions offer a number of plugins that extend the functionality of Papyrus UML for Aspect Oriented Modeling (AOM).