一些编程语言的参考库和教程

c/c++ reference: (C library, STL, ...)
http://www.cppreference.com/wiki/
http://www.cplusplus.com/reference/

java reference:
http://download.oracle.com/javase/6/docs/api/index.html?overview-summary.html

bash reference: (Advanced Bash-Scripting Guide)
http://tldp.org/LDP/abs/html/

python tutorial:
http://www.sthurlow.com/python/lesson01/
http://docs.python.org/tutorial/

php tutorial:
http://www.php.net/manual/en/tutorial.php

javascript. tutorial:
http://www.w3schools.com/js/js_intro.asp