SageThumbs - SageThumbs is a powerful shell extension allowing to preview enormous amount of image formats...
Xmind - Xmind is a brainstorming and mind mapping application.
MysticThumbs - MysticThumbs generates thumbnails of many image types not natively supported by Windows.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Icaros - Icaros is a collection of lightweight, high quality, Windows Shell Extensions
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.