[facebook] What programming language does facebook use?

I don't know much about programming languages, but am interested in a career with facebook, so I was wondering if someone could tell me what programming language facebook uses.

Also, do any other social networking sites use the same language?

might be surprised to know.. its PHP. read all about it here

Facebook uses the LAMP stack, so if you want to get a career with them you're going to want to focus on that. In addition they often have C++ and/or Java listed in their requirements as well.

One of the postings includes the following requirements:

• Expertise with C++ and/or Java
• Knowledge of Perl or PHP or Python
• Knowledge of relational databases and SQL, preferably MySQL and Oracle

Another:

• Expertise in PHP, JavaScript, and CSS.

Another:

• Knowledge of Perl or PHP or Python
• Knowledge of relational databases and
• SQL, preferably MySQL Knowledge of
• web technologies: XHTML, JavaScript Experience with C, C++ a plus

Source

http://www.facebook.com/careers/#!/careers/department.php?dept=engineering

Also, do any other social networking sites use the same language?

Some other companys that use PHP/LAMP Stack:

• DeviantArt (more focused on art)
• Twitter (for Front-End development)
• Google+

The language used by Facebook is PHP.

Also, do any other social networking sites use the same language?

The other one I know of is friendster.

Since nobody has mentioned it, I'd like to add that Facebook chat is written in Erlang.