Firefly UML
A free, easy-to-use and user-friendly Java-based UML editor.
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...