Visual Understanding Environment - Visual Understanding Environment (VUE) is a mind-mapping and concept-mapping tool.
TiddlyMap - An interactive concept- and mind-mapping plugin for the personal note-taking software TiddlyWiki based on the Vis.js library. It's free and open-source!
Flying Logic - Highly visual software for planning support used by strategists, process improvement specialists, teachers, and writers. Windows, Mac OS X, and Linux.
Wisdomap - Wisdomap Medicine is a study aid that helps medical students create differential diagnoses and suitable management plans from a presenting complaint and structured revision notes.
ThinkComposer - Software for create adaptable and multilevel diagrams, concept maps, mind maps and models
IOctopus - IOctopus is an online mind map service for a dive deep into the mind for the best ideas.