We identified some problems with Violet 0.21.0 and Violet 0.21.1 on Eclipse. Using this two releases, you are not able to edit properties on diagram's elements. This is mainly due to the AWT-SWT Eclipse gateway. We're working on it to publish a fixed version.
Note that this releases are OK when they are used outside from Eclipse (as a standalone program, Java applet or Java Web Start)
Violet 0.21.0 contains an improved undo architecture and a number of sequence diagram fixes.
Violet 0.20.0 is ready! This release merges the original project (Violet fom Cay Horstmann -> http://www.horstmann.co/violet\) with its Eclipse plugin.
The user interface has been changed to be more intuitive and offer more space for drawings.
Violet supports new features like undo/redo and proposes new activity diagram.
Its Eclipse plugin is now compliant with Eclipse 3.2
Go the http://violet.sourceforge.net for further informations.