Recycling code

Do not "reinvent the wheel". Aggressively search for and recycle other people’s code. This is especially useful if you are in the prototyping and not optimizing mode. Remember: almost everything you will come across has already been encountered, addressed, and documented; the biggest challenge is selecting the right keywords to find this information.

Unfortunately, currently many scientific packages written by scientists (not professional software engineers) can break or produce wrong results on new data sets, parameter values, or systems. Thus, the need for this wiki! When using other scientists' code test it thoroughly and, if possible, try to understand its details.

Here are some good language-specific packages.