Different times, different problems, apples, oranges. I agree with pg that lisp was probably the best tool he had available at the time for his specific proble

Different times, different problems, apples, oranges. I agree with pg that lisp was probably the best tool he had available at the time for his specific problem, ViaWeb was a system that generated systems, sounds like a lispy problem. And it also worth of note that not all of it was in lisp, so they mostly used languages that were good at each specific problem. If your problem involves shipping quickly and iterating, php, the platform is very powerful, especially at the time facebook started. So PHP may have been facebook's lisp, remember, rails and django were released on 2005, facebook started on 2004. So was php a bad choice? I don't think so. It might have been the best choice at the time. What you should take from pg's essays on lisp is not that lisp is the holy grail of programming, but that picking the best tool for the problem may play a big part on your success. Think about it, erlang is just perfect for whatsapp, so is lisp for ViaWeb's metaprogramming needs, and I think facebook didn't really have any big, complex problems at first, so picking the simplest, quickest platform to develop on was probably the best bet they could have made. So, yes, PHP was more powerful, or better put, more empowering than lisp for facebook's specific problem.