You once told me java can emulate the same quant lib functionality of
C/C++. I asked quants in GS, MS, ML, Barcap and a few other banks. I
don’t remember anyone saying their quant lib is in java. I now feel
there’s no industry momentum behind such a migration. Further, I feel there’s no justification either. I’d go out on a limb and say there’s justification for sticking to C.
A java implementation is less accessible from dotnet, C, python, and other scripting languages that are making (slow) inroads into trading floors. In contrast, all major languages support an decent interface to integrate with a C library. C is the common denominator.
More importantly, the sponsors of the quant lib are business users (not only traders) and they
know none of the languages but they know MSExcel. I’d say Excel integration is a must for any quant lib, otherwise traders may refuse to use it. C implementations easily integrate with MSExcel, via the
Microsoft COM interface.
Many quant libs are used in visualization and GUI. Dotnet and WPF are a market leader in GUI.
I also feel C implementation tends to be faster, at least no slower, than java quant lib. In pre-trade real time apps, a quant lib needs to be fast. A Barcap veteran told me the most important justification for
C++ in quant lib is speed.