The RAMSES patch based AMR simulation code.
MPgrafic large scale cosmological initial condition generator for simulations.
MUSIC large and zoom initial condition generator for simulations.
TIPSY N-Body simulation viewing software.
GIZMO Multimethod simulation code.
Fortran 77 tutorial.
Linux tutorial for beginners.
Shell script tutorial.
VIM Adventures - an interactive game to learn the basics of VIM.
F2PY - a nice way to cross compile fortran modules to be read in by python scripts.
bento tutorial on everything you need to know about web development.