I'd bet it might be a problem with you trying to send Apple Events from a different user (www). This is getting out of my range of Mac-fu, but you might try enabling Remote Apple Events under System Preferences / Sharing and see if that works. You might also try setting up the CGI to run under your userid with suexec and see if that works.

Addendum: And if you can't get BBEdit to work you might look at htmltidy, which probably will compile on OS X without much trouble.