Visual Understanding Environment - Visual Understanding Environment (VUE) is a mind-mapping and concept-mapping tool.
Xmind - Xmind is a brainstorming and mind mapping application.
ShuffleInspire - ShuffleInspire seeks to provide inspiration and boost production to builders and makers in the online community.
FreeMind - FreeMind is a premier free mind-mapping software written in Java.
Aibase - Creative Data Manager
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.