On Tuesday, February 2nd, Facebook announced a new runtime for PHP, called HipHop. It was rumored that this project was an under the table sort of thing.   However it turns out, HipHop is not just a runtime, it’s also a new webserver and has been powering 90 percent of Facebook’s servers for months now.  Starting this Tuesday evening you should be able to a look at the GitHub respoitory for HipHop, the  HipHop wiki or join the HipHop developer mailing list.