Not the music. No, developers from facebook hacked up HipHop. It’s basically a compiler for PHP that turns PHP code directly into C++ which is a huge improvement on performance on both memory and cpu useage.
I hope in the future more HipHop like compilers will be released (Opensource?) so that PHP is more scaleable than it’s now. Ever experienced Facebook’s speed? Well, it’s think the speed is good. So let’s release HipHop to the public, or something like that.
Read more on Facebook’s-developers-blogpost.