[boyter]

There are a few other code search engines which search across publicly available code though if that's what you are looking for.

http://code.ohloh.net/ https://github.com/search?q=malloc&type=Code&ref=searchresul... http://searchcode.com/ http://codesearch.debian.net/

Symbolhound is also quite interesting, http://symbolhound.com/

Full disclosure I wrote and maintain searchcode.

[markelliot]

Notably absent from your list is http://grepcode.com -- which IMO has one of the best interfaces around, with compiled code docs and some java-centric implementation and invocation links for java code they index.