Google Code search is a powerful open-source code search launched in October 2006.  It gives you the public source code and the class definitions of almost many languages and web script technologies.

Though it is a beta version, has been optimized well and gives accurate results.  Take any programming language keyword and type it as a search keyword, It instantly gives you the necessary commands and descriptions with external links and class definitions.

A simple Print command gives you all the possible options from Java, C, Python and also shell script to name a few. Different technology users would now be able to get instant help without going through particular websites or links.

Steps:

1. Open Google code search using the link http://www.google.com/codesearch
2. Type any keyword or function name and it will give you the entire list for different languages.

Interesting thing is that Google stores a cached copy of all source code and gives you the dump of it.