XMIND – Portable Mind Map
XMIND is an Open Source Portable Mind Mapping Software. It is an easy to use charting software that's commonly used for Brainstorming sessions, personal mind mapping or to capture knowledge and ideas for projects and project management. The information within a chart or map can be shared online, shared internally or kept as a personal mind map.
Portable Mind Mapping – XMIND Screenshot

Authors Website: xmind.net
License: Open Source
Download: You can download this Portable Mind Mapping Tool HERE