NetBeans

Open Source / Non-Proprietary

available in NetBeans 6.0 full edition, or as a downloadable plugin in Plugin Manager, or with NetBeans IDE 5.5 Enterprise Pack

Forward and Reverse Engineering
Designers and analysts design applications using the UML modeling language, then developers generate Java code from the UML model. You can also update the model from changes made in the source code.

Generated source code can be saved into new source files or merged into existing source code files providing full round-trip engineering capability. Your collection types are preserved during Forward and Reverse Engineering and may be set and changed.

UML Diagram Types
With NetBeans UML Modeling, you can create 8 UML diagrams: Activity diagram, Class diagram, Collaboration diagram, Component diagram, Deployment diagram, Sequence diagram, State diagram, and Use Case diagram. You can align diagrams visually in the Diagram Editor.

Customizable Code Generation
NetBeans UML provides template-based code generation for Forward Engineering. Modify the FreeMaker templates included with the NetBeans IDE to customize how code is generated.

Integrated UML Tools
Requirements Gathering: Bring application design requirements into your model via an XML file, or import them from the Telelogic DOORS® requirements tool. Create Javadoc style web reports from your model to share your work with others.

There is a full set of predefined and extensible design patterns including EJB 1.1, EJB 2.0 and Gang of Four.

http://www.netbeans.org