My original question was "Why does google limit the number of programming languages used internally?"
I stand corrected on this question. Originally I thought google only used:
Java, c++, and python
: to limit the languages in use at google. But after talking to a couple of friends who work there I found they use Ruby, Haskell, Scala, and Erlang, and other languages too, although sometimes these choices are "frowned upon" to quote a friend :)