programming

http://ipsur.org/ An introductory textbook to statistics and the R programming language.

http://atgreen.github.com/ggx/ A step-by-step guide to adding support to the GNU toolchain for a new architecture.

https://github.com/mirrors/perl/blob/book/perlsecret/pod/perlsecret.pod Perl's list of secret operators.

http://me.veekun.com/blog/2012/04/09/php-a-fractal-of-bad-design/ A comprehensive collection of criticisms of the PHP language and its standard library.

http://www.slate.com/articles/technology/technology/2012/03/ruby_ruby_on_rails_and__why_the_disappearance_of_one_of_the_world_s_most_beloved_computer_programmers_.single.html A comprehensive history of Why the Lucky Stiff, the king of Internet hipsters.

http://www.youtube.com/watch?v=HM1Zb3xmvMc#t=2m43s Every programmer should learn a little Lisp!

http://www.lurklurk.org/linkers/linkers.html This is a pretty comprehensive introduction to linking in C and C++.

http://lambda.bugyo.tk/cdr/mwl/ A Japanese manga guide to the programming language Lisp.

http://doryen.eptalys.net/libtcod/ libtcod is a library for writing Roguelike games.

http://www.blue.sky.or.jp/grass/ Grass is a programming language that consists of only the letters v, w, and W.