EMF Views is an Eclipse plugin that brings the concept of database views to the modeling world
JTL is an EMF-based tool that allows you to design and manipulate models, maintain consistency and synchronize software artifacts, keep traceability during design.
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:
Papyrus extensions offer a number of plugins that extend the functionality of Papyrus UML for Aspect Oriented Modeling (AOM).
RCRS (the Refinement Calculus of Reactive Systems) is a compositional reasoning framework