Breefly, server side includes is a very small part and is neither php nor perl. Apache has SSI available though with PHP is probably not really necessary. I'll bet things would be more secure with server side includes in effect. One example of a server side include might be a function for giving out the date last modified of a page in your web site. CGI are usually perl scripts that get executed with post formactions or by a direct URL. They stand alone but run on the server. PHP may seem similar but it is embedded in your HTML; or at least it is with every example I've seen so far. It is also server based as opposed to client side scripts like java script, perlscript, vbscript, etc. Those run on the user's machine instead of the server. that's where lynx falls flat on its face; it cannot run any client side scripts. Hence our continual complaints that some web site here and there runs javascript and us lynx users get left out in the cold!
