Here is a list of programming languages in which I write code.

Java

for Algorithms, Part II | Coursera

C

for The Hardware/Software Interface | Coursera

Objective-C

for Coding Together: Developing Apps for iPhone and iPad (Winter 2013) - Download Free Content from Stanford on iTunes

Python

for work

Perl

for work

Ruby

for work and fun

Conclusion

Comparing languages with each other is so interesting that I need more languages:)

cf. TODO