[PhillipT]

Rather than guess - I'd recommend asking. Most places will be happy to explain what languages/tech they use to an incoming employee and many will be happy you asked. Ultimately they are recruiting you because of your skill profile and trying to find the best place for you since in the long run it will benefit them (and hopefully you). So ask your recruiting contact for more info - and when you do so mention what you have found in your research and readings - because it (a) shows your committed and (b) will help them quickly see what are relevant possibilities.

The quants i know in finance have varied backgrounds but are predominantly maths, comp.sci and physics backgrounds and all asked similar questions on entry into their banks and financial institutions. As for languages they work with a range of tools including Matlab ,Mathematica and K for those on research side to C++, java, Python (wrapping C++ libraries), K /Q and R for those on production and reporting side. (edit - there are some who also use .net - but i forgot about them :-)) What tech is used will really depend on the bank. As a quant your job will be to work out how to implement and maintain algorithm, systems and tools around their tech environment - so it is probably better to be open on the language side and look at it all as huge good learning opportunity (which it is) and find a spot where the subject matter is going to intrigue/interest you. Again hope this helps.