FreeMind - FreeMind is a premier free mind-mapping software written in Java.
XMind - XMind is a brainstorming and mind mapping application.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
TheBrain - TheBrain: The Ultimate Digital Memory
MindManager - With MindManager, flexible mind maps promote freeform thinking and quick organization of ideas, so creativity and productivity can live in harmony.
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.