Rosetta Code

Awesome programming resource for comparing different programming languages:
Rosetta Code is a programming chrestomathy site. The idea is to present solutions to the same task in as many different languages as possible, to demonstrate how languages are similar and different, and to aid a person with a grounding in one approach to a problem in learning another. Rosetta Code currently has 396 tasks, and covers over 200 languages, though we do not (and cannot) have solutions to every task in every language. (Though you can help with that!)

A variety of tasks are listed, and visitors to this site are invited to solve the tasks in the language of their choice. The tasks cover everything from the mundane Empty Program to the classic Towers of Hanoi, the practical User Input, the mathematically-inclined Lucas-Lehmer test, and the involved yet entertaining RCRPG.