HPHP Initial Comment
HipHop what you need to know

HPHP appears to be a significant product: a PHP compiler that compiles down to native binaries, saving time and CPU. It produces a monolithic, multithreaded binary.

A nice side effect could be that sites using HPHP would be a harder to hack. For one, you could never upload and execute a PHP script, because PHP is not running on the server.

HipHop leverages a simple fact of PHP-life: most of your code doesn't change. Even in a project with ongoing bugfixes, only a small number of changes are deployed. So, once the app's done and ready to be run full-time, it should really become a compiled application. HipHop is the compiler.