I just want to share with what Mac wrote the other day that Facebook uses PHP & since then i have experienced that when you open for instance Homepage on Facebook,you will see www.facebook.com/home.php?ref=home
yesterday when i logged in on FB i got a message: Cookies required:Cookies are not enabled on your browser.I dint take notice of such things before learning PHP and I think its interesting that i can now observe & understand things that i didnt know before registering PHP.