Dominant language by industry?

Hey guys, What is the most popular language being used in your industry / sub-industry? Who uses them and why? Please forgive me for my ignorance, but:

From what I know: Python and R are very popular as of late in the world of quantitative Finance.

Python is also quite popular in astro-physics and my friends tell me that it is replacing Matlab.

Okay, your turn :)

Edit: Looks like C++ is very popular in the quantitative analytics space as well - mostly due to speed and low latency. A ton of jobs ask for C++ and quite a few like C#.