Actually, Facebook has a very sophisticated infrustructure. Take a look at Thrift, http://developers.facebook.com/thrift/, the open-source project for cross-language development they released earlier this year. Even Google is trapped using about four programming languages (C++, Java, Python, and JavaScript). The latest version of Thrift has interfaces for 10 languages (Cocoa, C++, Erlang, Haskell, Java, OCaml, Perl, PHP, Python, and Ruby).