ArgoUML

This software does a lot Activity Diagrams (Flowcharts), Class Diagrams, other stuff I don't do like Case Diagrams. Lots of stuff.

It is Java, so it goes anywhere, it doesn't cost anything. On my Kubuntu Linux machine it is the most responsive tool I have used-- no lag in the typing or anything I ask the mouse cursor to do.

The one thing I noticed, which is why I marked in incomplete, is that there is no cutting and pasting. That crucial feature is marked on the development web site as something people want and various implementation options are discussed, but in the current final product it is not a feature available. I do fine without it.

I like this much more than Dia. And I haven't had to shell out hundreds of dollars for Visio (or use a crummy Microsoft Operating System).