There's a gold mine of code available to programmers, but choosing the right library and understanding how to use it can be tricky. We created Sourcegraph, a fast, semantic code search and cross-reference engine, to help developers like you discover and understand code better.
Sourcegraph semantically indexes all the open source code available on the web (in multiple languages). You can search for any definition in code and see everywhere it’s being used. When viewing code, everything is clickable (with jump-to-definition links) and has documentation/type tooltips. And you can do all of this in your web browser, without needing to configure any editor plugins.
UPDATE: Sourcegraph now supports all popular languages.
If you’re an author (or user) of an open source project or library, you should sign up and index the code on Sourcegraph. This lets contributors and users of your libraries search and browse the code on Sourcegraph. These features can help your users save hours by letting them quickly find and understand pieces of code. A single good usage example can be worth a thousand words of documentation. Indexing repositories is free and always will be for open source (and private code).