Which languages do you use for which purpose?

Question

I don't use just a single language for every purpose. Instead I try to use a language that fits best to the specific task. I would like to hear which languages and for what purpose you are using. Please tell me why you think your choice is best match. Maybe name also your preferred frameworks to reason your choices.

Currently I am using:
Web Development: Ruby on Rails
Scripting: Python
Efficient and hardware oriented software: C++ (with CUDA)
3D Graphics: C++

Maybe you will inspire me to try something new

Answer 1

For graphics I used some frameworks like http://www.ogre3d.org