http://pres.derickrethans.nl
http://www.mnot.net/cache_docs/
http://www.w3.org/People/Raggett/tidy/
http://www.schroepl.net/projekte/mod_gzip/index.htm
http://www.php.net
http://www.squid-cache.org
http://www.webreference.com/authoring/languages/html/optimize/