Open Source Data Modeling Software

Firefly UML is a 100% pure Java application designed to create and edit UML conform diagrams. With class diagrams, sequence and instance diagrams, Firefly UML provides a solid selection from the vast range of existing UML diagram types. Firefly UML is really easy to learn as it provides you multiple ways of access to the same function - be it mouse action, hotkey, context menu or toolbar icon. And the best thing is: once you have learned how to handle one type of diagram, you also have learned how to deal with the other diagram types, because they all follow the exactly same user interaction patterns. Besides being user-friendly, Firefly also offers powerful features which other free editors usually do not. For example, you can import your existing Java project into Firefly and generate nice-looking class diagrams within a matter of minutes. You can also go the other way around and export your model as skeleton Java code.