"MetaCompress is an ISAPI filter for IIS (Internet Information Server). Most of the web browsers, including the most popular Microsoft Internet Explorer, can access compressed content of web sites as well as ordinary HTML pages. If a site packed with MetaCompress is accessed by a client browser supporting compressed content MetaCompress packs text on the fly. Otherwise, MetaCompress leave required content uncompressed.
This feature gives you the incontestable advantage: text content of your site will load faster.
That will increase your site accessibility for users who have slow dial up connection (14400 - 19200 bps) and speed up the page loading on your site in general."