In fact, I find libraries to be an essential tool for a researcher in a hurry to prototype ideas - which often involves solving non-trivial sub-problems. So, what libraries are you using in your every day endeavors?
Here are my favorites (I'll skip the basics such as libpng, zlib, etc.):
- Loki - the libary that made me realize what templates are for. Andrei Alexandrescu's book is a must read!
- TAUCS - linear solver for sparse matrices
- ANN - approximate neighbor search
- AntTweakBar - GL/D3D gui, simple, clean and powerful
- LUA - scripting, very easy to integrate
- tolua++ - makes lua even easier to integrate with c++
- TClap - command line parameters, template based
- ODE - physics
- Bullet - physics
- fftw - fast Fourier transforms
- SDL / SDL_net - media library. I essentially use it for multiplatform threads and networking. A bit old-school but still very effective.
Now, some libraries I am planning on using much more regularly: