CHESS implements the CHESS UML/SysML profile, a specialization of the Modeling and Analysis of Real-Time and Embedded Systems (MARTE) profile
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:
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).