What softwares, development tools, languages did you use in your company? I often learnt that VB, C++ languages, MatLab software are among the most popular, is that true?

Any open-source program is used in Finance Industry ? How popular Unix ( Linux in particular) in IT department ? Thanks

Lots of open source used in finance. Apache web server is probably the most common, and MySQL popping up in lost of places, for tactical stuff. Lots of utilities used in IT departments are some form of open source. There is Quantlib, which looks promising as an open source Quant framework.Most firms have some Linux somewhere now. It is growing but is still mainly in specialist tasks. Mainstream work is still mostly proprietary Unix (HP/UX, AIX etc), Windows, and there is quite a lot of interesting stuff like VOS, OS400, OS/2, VMS, VME still around.

Lately I've been using the R statistical language, which is open-source S. I read once that free software is only free if your time is worthless. Sometimes I think that's correct.

I can think of at least 4 major places that are at the moment replacing their Sun boxes with many redundant cheap Linux machines. Makes a lot of sense for applications that need either a lot or little power. "crap apps" run well on single processor Intel boxes that cost maybe half what a comparable power Sun machine would set you back; and very computationally intensive stuff (Monte Carlo similation, Mark to Future VAR being two classic examples) works well on clusters / arrays of linux boxes.I cant think of any of the major houses that dont have shed loads of Perl as the code glueing all of their trading systems together (though would be interested to hear otherwise!).The Gnu C/C++ compiler is one of the best and most powerfull out there - and since Sun stopped shipping a C compiler a lot of places use this for their own internal dev work. Interestingly the Algorithmics VAR engine is a Gnu C++ app.Apache / Tomcat are pretty much the web server of choice and I know that Enhydra has a good foothold on developers boxes since Websphere and WebLogic are both hideously expensive to develop on - it's good quality too. You will usually find some SAMBA sitting out there giving PC users access to Unix files too.

How about Java ? J2EE ? C#? .NET?