This book is based on a Web site, whatis.com, created by Lowell Thing in September, 1996, as an experiment in hypertext and also as a place for some information he was always forgetting. The original idea was to see how many useful hypertext links could fit on a Web page, and he wrote the first few topics in order to see what the idea would look like. One topic led to another and, by mid-2001, Lowell and some freelance contributors had written 3,500 definitions. In February 2000, Whatis.com was purchased by TechTarget, a diversified media company providing targeted IT media to technology professionals. Lowell continues to play an active role as Editor of the site. Whatis.com currently serves more than one million visitors each month.