index.php
 

if I have only index.php in my main directory, and nothing else but folders, will that file load when someone types in the domain, even though its not an html file?

yes

If you have "DirectoryIndex index.php index.html" in httpd.conf yes.

Yep right !

:glugglug

I beleive almost all servers are set up to read .html, .php, or .shtml, whichever the index is.

Least i have never had to ask for them to configure it to see them