The explosive growth of World-Wide Web resources in the past year has inspired several contenders for the title of 'best Web search engine'. The different keyword indexes of Web resources feature a wide variety of search interfaces and capabilities. There are many Web keyword indexes, and some of them are: Lycos; WebCrawler; World-wide Web Worm; Haevest Broker; CUI. These research indexes permit Boolean searches and other sophisticated search options, but all suffer from the problem of overload. One possible solution to the overload problem is to limit the number of users by charging for the service.