Programming for a mathematician?

I have started studying Haskell. I expect the type system and monads to be the most interesting things to learn (I know common lisp and have already seen many cool features). Though the days of general programming are long gone. I am interested in writing math apps though. Should I continue learning Haskell or should I start studying Mathematica (or some other alternative like matlab/maple) instead?

I am interested in writing math PROGRAMS though.*

Oh silly me, where did I get the idea of ``apps'' from and where did I get the idea of calling programs them?
_{yeah fucker, where did you get the idea?}