Workflowy - A better way to organize your mind.
Xmind - Xmind is a brainstorming and mind mapping application.
Dynalist - Dynalist is a web app that lets you break down and organize your thoughts in the format of lists.
Visual Understanding Environment - Visual Understanding Environment (VUE) is a mind-mapping and concept-mapping tool.
SuperNotecard - Introducing SuperNotecard. SuperNotecard is an online writing tool that features virtual notecards to help arrange facts or scenes, track details, organize paragraphs, and clarify your composition process.
FreeMind - FreeMind is a premier free mind-mapping software written in Java.