There is a new search engine for code search- All The Code. The existing engines are Krugle, Koders and Google Code Search. Presently, the serach engine returns data only for java language and more languages will be added slowly. The distinguishing feature is that All The Code considers the relation between code and uses this to help judge the relevance.
Search Engine Watch reports that Google Code which is a searchable repository of publicly accessible code gathered from across the Internet whereas Koders does not rely on code search from public domain as Google. In fact, the engine is moving into closed environments to access exclusive codes. Given that Google is already doing well, All The Code has tough competition to face.