As much as I'm not a PHP fan these days, you are completely correct. In 2003, you had CFM (which MySpace actually used at first), Java (and probably some overly complex framework like Jakarta Struts to go with it), CGI, or the new ASP.net. For a college student to do a quick HTML doc with some code interspersed here and there, PHP sounds like the ONLY viable option that didn't have you spending money on licensing, or setting up some huge infrastructure.

I used PHP/MySQL too as it was just dead simple for most things.

Perl was a possibility, but CGI is/was a pain to use. To get started you had to understand things like headers. You frequently had scripts refusing to run for whitespace issues relating to CRLF vs LF. You'd need to come up with your own templating language... It was just much more difficult.

Also Perl libraries typically require superuser rights to install. That's a big deal if you're a poor student using shared hosting on your fun hacking projects.

Python really wasn't an option. mod_python by default required you to restart Apache whenever a python file changed. It was designed to be configured by sysadmins on dedicated servers... if you wanted something you could hack together an put on a shared host, it just wasn't an option.

Also the hot Python framework in 2003 was Zope. No one uses Zope anymore. For good reason.

Ruby was much smaller, and this was pre-rails so it didn't have any significant web framework. I'm not even sure if there was a production ready way of hosting ruby scripts.

I believe Python might have worked. It's grown well as a web development language since then by itself. It may have forced several rewrites before WSGI came about. It is a relatively easy language to learn, to hire for, and has few massive warts. (Ruby is roughly in this category too, in my opinion.)

I believe Perl probably would not have worked. It hasn't grown much as a web development language since then (although it has some great web frameworks). The language itself has languished in both development and community growth, and it fairly esoteric and certainly harder to learn than Python and PHP, and would have been harder to hire for. It seems unlikely that pre-2010 Facebook to meaningfully have changed the trajectory of the language (ie, Perl 6 being a success).

I don't think Java, C++ (or C), Cold Fusion, ASP, Haskell, Ocaml, and many other languages would have worked, for a bunch of reasons. Harder to hire for, harder to iterate with, more costly in terms of infrastructure, harder to teach/learn, and so forth.

PHP isn't a totally insignificant part of Facebook being as successful as it has been. A good-enough language choice was necessary, at least, and PHP it seems was a good-enough choice.

The point you "Anything but PHP" guys seem to conveniently ignore (or perhaps, not comprehend), is that at Facebook scale, you are going to have issues with many of these things regardless of what language you chose. They have specifically made this point many times. You and others point to some hand-wavy magical language which somehow doesn't have any issues when serving hundreds of millions of users. That doesn't exist.

Do you think perl would have been much better? Either way, the point that he was making was that there were pretty slim pickings back then. Certainly the dominant languages/frameworks of WD these days (python, ruby, node) didn't exist. Or by another token, the only dominant one that was also strong back then is PHP, the one they chose.

I disagree. Perl would have likely crippled them, due primarily to the lack of Perl engineers.

Pretty much only the front-end code is written in PHP (or Hack, I guess).

Services (things like the feed, the typeahead, graph search, messages, &c.) are written in C++ and other languages - ie, the things it is sensible to write them in...