I recently downloaded a copy of FreeMind, an open-source mind mapping program written in Java, and have started to play around with it. When I looked at it a few years ago, it still appeared to be a bit rough around the edges. But it has certainly matured significantly since then. FreeMind now boasts a very polished user interface and many nice features. Significantly, it supports numerous keyboard commands for common operations, which enables you to add content to your map and modify it quickly. The program offers a full set of topic formatting and linking options. And I also like the ability to quickly "fold" and "unfold" map branches with a single keystroke.
Watch for a full review of this much-improved program in the next several weeks on InnovationTools.com.