Visual Understanding Environment - Visual Understanding Environment (VUE) is a mind-mapping and concept-mapping tool.
Aibase - Creative Data Manager
Protégé - Protégé is a free, open source ontology editor and knowledge-base framework.
3D Topicscape - 3D Topicscape is a Personal Information Manager that provides a template loosely based on...
Flying Logic - Highly visual software for planning support used by strategists, process improvement specialists, teachers, and writers. Windows, Mac OS X, and Linux.
FreeMind - FreeMind is a premier free mind-mapping software written in Java.