ThoughtStack is a freeware tool for brainstorming, planning, note taking and thought organization. It is a simple tool designed keeping in mind the need for an advanced notepad for organizing thoughts. It lets you enter the thoughts into a tree structure for better understanding. Now create tree hierarchies or outlines with your ideas using this software tool. It supports hotkeys so that you can control everything with keyboard. The interface is very intuitive with tabbed structure to let you work with multiple objects at the same time. For those who believe that outlining is a very good way of organizing thoughts, this tool is a must have.