- For writing/displaying games, the packages by Martin Osborne are helpful.
- For graphs, tikz is a useful package. See the excellent short introduction by Jacques Crémer.
- For simulations, symbolic computation and numerical solving I use Python, especially the packages NumPy, SciPy and SymPy. (I can never remember which of these packages is part of which other package; Anaconda is a good platform that has everything you need to get started.)
- For empirical work, I have been working with R.
- All of these programs and packages are open source and free.
- Graduate students starting out in the social sciences (or experienced researchers who wonder whether they can improve their process) may be interested in Kieran Healy’s Plain Person’s Guide to Plain Text Social Science.