Wikipedia is an encyclopedia - a collection of all types of knowledge - written by its readers. It is free for everyone to use, to edit, and to share. You can edit it yourself : visit wikipedia.org and follow the "edit this page" or "discussion" tab on the top of any of the pages.
For a set of articles edited for schoolchildren, see the schools wikipedia. You can also download a selection to browse offline on your XO.
As of late 2007...