Any of the "academic" languages (Haskell, ML, Lispen, etc) are probably more likely to be found in math/physics-heavy development than in general development sh

Any of the "academic" languages (Haskell, ML, Lispen, etc) are probably more likely to be found in math/physics-heavy development than in general development shops, but C/C++ is probably the standard (for fast-math libraries and realtime work) - you may see old fortran for some numeric stuff, and forth for some embedded work. Java is pretty rare, AFAIK. I think HN is not the best place to ask about "languages to learn to get a job", though.