That's a server, not a browser ;)

I was using FORTRAN, Erlang, and Python as examples of languages which are heavily used in industry, but have neither the crushing popularity of Java/C# or the pop-culture appreciation of Ruby or Javascript. It doesn't really matter how much Haskell or Erlang are used, or how many billions of dollars pass through their runtimes every day; for whatever reason, the Internet has decided they are not popular.

Quite obscure, but I was surprised to find that a 3D modelling program, Wings3D, that I've used on and off over the years, is written in Erlang.