ArgoUML

ArgoUML Publisher's Description:
ArgoUML is the leading open source UML modeling tool and includes support for all standard UML 1.4 diagrams. It runs on any Java platform and is available in ten languages. See the feature list for more details.

ArgoUML uses GEF, the UCI Graph Editing Framework to edit UML diagrams. The following diagram types are supported:

* Class diagram
* Statechart diagram
* Activity diagram
* Use Case diagram
* Collaboration diagram
* Deployment diagram (includes Object and Component diagram in one)
* Sequence diagram

XMI Support

XMI is an XML based exchange format between UML tools. ArgoUML uses this as standard saving mechanism so that easy interchange with other tools and compliance with open standards are secured. Additionally, exporting the model to XMI is possible. XMI version 1.0 was used for UML 1.3. ArgoUML 0.20 imports XMI 1.0 (by converting UML 1.3 to UML 1.4). And ArgoUML imports the UML1.4 formats XMI 1.1 & 1.2, but only writes XMI 1.2.
Several diagram export formats

Diagrams can be saved as GIF, PNG, PostScript, Encapsulated PS, PGML and SVG.