I got this information from http://boardreader.com/info/about.htm
BoardReader was developed to address the shortcomings of current search engine technology to accurately find and display information contained on the Web's forums and message boards. Founded in May 2000 by engineers and students from the University of Michigan, Boardreader uses proprietary software that allows users to search multiple message boards simultaneously, allowing users to share information in a truly global sense.
Our technology is based on innovative, scaleable software created to quickly and accurately search information contained on message boards. Message boards are part of the Internet known as the 'Invisible Web' and pose many problems to traditional search engine spiders. The dynamic content is usually very deep and hard to search. In addition, many of these sites change their locations, servers, or url's almost daily presenting special searching challenges.