Microsoft introduced OneNote as part of their Office Suite since 2003 and while it gained popularity in Office 2007 onwards due to the tighter integration with Outlook and Word and also due to the licensing and distribution changes (now ships with standard Office Suite), it still remains to achieve a regular membership of the Office family for years to come. The strong point of OneNote is its real time collaborative features which gives it a shared whiteboard feel which can accommodate most media types, text, images, video, audio, Office objects (visio shapes, excel sheets etc), handwriting (for Tablet PC) and a good flexibility for use the writing area like a physical scrap pad. What it lacks though is a systematic structure of representing information which can be good at some scenarios. Unlike FreeMind or ThinkingRock which are backed by particular knowledge representation schemes, OneNote is for the free souls to use as they please.
This approach suits many individually but cant be relied upon in team based project sharing and collaboration. Although OneNote pretends to present well organized templates, it actually does not do much more than enter default bulleted “flat” text.