Graphviz

Markdown is allowed here. The short description describes the project briefly, it should not be longer than one or two sentences.

Freeplane

Freeplane is a free and open source software application for bulding mind maps.

FreeMind2

FreeMind is a premier free mind-mapping software written in Java. A mind map is a diagram used to visually organize information. A mind map is hierarchical and shows relationships among pieces of the whole.