Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Eclipse Papyrus - Eclipse Papyrus is an industrial-grade open source Model-Based Engineering tool. Eclipse Papyrus has notably been used successfuly in industrial projects and is the base platform for several industrial modeling tools.
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
Topcoder - The Topcoder home page has received a slick new makeover that lets new customers quckly login, discover the power of our community, and launch challenges.
ARIS Express - ARIS Express is based on the proven ARIS methodology and industry standards.
Violet UML Editor - Violet is a UML editor with these benefits: Very easy to learn and use. Draws nice-looking diagrams.