ArgoUML is an open source UML modeling tool that includes support for all standard UML 1.4 diagrams. It runs on any Java platform and is available in ten languages.
Web Site: http://argouml.tigris.org/
License and Pricing: Open Source, Eclipse Public License (EPL) 1.0.
Support: User forum: http://www.argouml-users.net/forum/
Resources
* ArgoUML – Open Source Unified Modeling Language
* Argonaut’s life: the blog from a ArgoUML contributor
* Reverse Engineering Java Code with ArgoUML, Jude Share, Sun NetBeans and IBM Rational Software Architect