Facebook was originally written in PHP. What technologies is it using now?<p>I had someone tell me that they were moving from python/django to php because 1. it's easier to find PHP devs and 2. it's good enough for facebook. Is it?
Really?!<p>They developed Hip Hop to transform PHP into C++, so I'd bet they are firmly dedicated to PHP, and I really doubt that Facebook has any problems finding developers.<p>PHP/C++, Cassandra, JavaScript, Flash, and whatever third party developers choose to use as long as they use the Facebook API.<p>I don't actually know, maybe someone else will give you some more insight, but I'm pretty confident about the PHP part.
It's always been written in PHP, and they released a compiler for the language that they developed in house:<p><a href="http://www.insidefacebook.com/2010/02/02/facebook-open-sources-hiphop-php-compiler-software/" rel="nofollow">http://www.insidefacebook.com/2010/02/02/facebook-open-sourc...</a>
Facebook developed the Thrift API to facilitate cross-language services: <a href="http://incubator.apache.org/thrift/" rel="nofollow">http://incubator.apache.org/thrift/</a><p>I imagine they could use anything as long as it consumes Thrift. The extent to which they do that is a question.
Take a look at the EE380 video for May 5, 2010 at <a href="http://ee380.stanford.edu" rel="nofollow">http://ee380.stanford.edu</a>. Haiping Zhao from Facebook describes the <i>HipHop Compiler for PHP: Transforming PHP into C++</i>.
It's easier to find PHP devs.<p>Facebook is written in PHP. They crossed the point where switching made any sense a long time ago.<p>This has absolutely nothing to with what you should use.
From people on the inside.<p>Its written in PHP mainly. It has Java, C++, C, Haskell, Erlang, Python, Perl, OCaml and some others littered throughout the site.