- A facility that lets you search for information on the Internet from an index, that typically holds references to all the text on WWW pages. The indexes may relate to the content on one site (e.g. a version of Excite indexes the ETO Web pages daily) or hold references to WWW pages all over the Internet (50 million plus). Commonly used engines are Lycos, InfoSeek, AltaVista, and Excite. Selection of pages to index may be manual (a creator submits pages for indexing) or automatic, where a 'crawler' or 'spider' (intlligent agents q.v.) roams the net to find new and pages.