The practising mathematicians I know don't program. I'm not sure if there are any ways in which programming can help with things like Functional Analysis or Ge

The practising mathematicians I know don't program. I'm not sure if there are any ways in which programming can help with things like Functional Analysis or Geometric Topology. Not even sure about low-dimensional topology. I'll ask Tim Gowers next time I see him. The ex-mathematicians I know who now use mathematics to do things in the real-world use a full range, including all those mentioned elsewhere. For my PhD I used Fortran, BCPL, zed (not the one you might think - it was essentially "ed"), and Phoenix scripting. For my day job I use Python/Sage/NumPy, C, C++, ARM assembler, bash, BASIC and OpenOffice Calc. Infrequently and irregularly I use Lua and Scheme. On the other hand, I'm not really doing math anymore. I no longer prove theorems.