<i>Because of differences like this ... I believe that the work done on HipHop represents a fundamentally smaller challenge than that taken on by the teams working to improve the implementations of languages like Python, Ruby, or Javascript.</i><p>I think this is true. On the other hand, it's not Facebook's job to do research. If they can benefit equally from solving a simpler problem, then that's what they should do.<p>I agree with the author's points, I just want to make explicit that Facebook didn't make wrong choices. It's just that their work is probably of limited value to everyone else.