Umbrello is the premier UML diagram tool for Linux desktops. UML is a standard for making diagrams of software, useful for documenting and planning your programs.
I took over Umbrello in about 2002 and maintained it as part of my University final year project. One of the first changes that I made to Umbrello was to make it a KDE project, it was the natural home. But I never moved the website or mailing list, Sourceforge was good enough.
Many years later and I have not been contributing to Umbrello for some time but it fits a gap in the Free Software world and there's been enough interest to port it away from Qt 3 compatibility classes so it should exist in the move to KDE Frameworks 5.
And now thanks to Ralf Habacker it has finally been moved completely to KDE infrastructure with a lovely new website umbrello.kde.org.
I've been surprised that nobody else has taken a similar path as I did a decade ago. Academics love UML and students should love working on software people actually use, so using Umbrello as a university project will be a guaranteed A. I won a big award recognising the best university software projects in Scotland when I did it. So if you're in your last year of uni after this summer and looking for a dissertation, do consider Umbrello, plenty of bugs to fix, features to add and the whole Qt 5 porting to do.