Programming languages: C, C++, Common Lisp, Scheme, Perl, Python

Mathematics systems: Matlab, Maple, Mathematica, R, Sage, LaTeX

Database systems: DB2, MySQL, PostgreSQL, Sybase

Revision control systems: git, svn, cvs, rcs

Operating systems: Unix, Linux, macOS, Windows

Special toolkits: ITK, OpenCV, wxWidgets, Virtual Cell, ImageJ