This is software I've found useful and has improved my ability to do research. Let me know by email if you have any suggestions, improvements or criticism. You can find these by searching on google.
QuTiP: The toolbox named as "Quantum Toolbox in Python" mainly helps us to calculate the time evolution of a small quantum system, especially under an influence of some noise. The website is http://qutip.org/.
Wikibooks: For linux users, the latex editing sometimes needs us to remember lots of commands. Wikibooks gives us useful resource as appeared in https://en.wikibooks.org/wiki/LaTeX.
Google Sites: I use the templates, easy customizability, and instantaneous updating to make my website and create wiki-style pages. There may be something better.
Maxima: When we need to find the eigenvalues of a 3 by 3 matrix in symbolic forms, Maxima is useful and free. The tutorial can be found at http://maxima.sourceforge.net/docs/manual/intromax.html.