Talk:HipHop

XHProf
XHProf discussion is orthogonal to HipHop as XHProf is a Zend PHP extension (not a HipHop one). My understanding is that HipHop does implement a XHProf-like interface somewhere in its codebase that may or may not be API compatible with XHProf

Missing discussion of HHVM
We probably should add a discussion on that HipHop on MW is deferred (currently) until HHVM is available in late 2012.