XMindSeptember 3rd, 2009
In the light of the previous post about creating Functional Mindmaps, XMind is another open source tool to help with just that. The software is available for Mac, Windows and Linux, and allows to brainstorm ideas in a social way. Mind maps can be generated to explore abstract requirements or ideas. After a mind map is created, the document can be shared online free of charge. XMind also comes in a Pro version which allows to share your work privately. Pretty cool.
Download it here.