- https://searchcode.com/ searchcode
- http://www.codase.com/ codebase
- https://sourcegraph.com/ sourcepraph
- https://www.openhub.net/ openhub
- http://www.grepcode.com/ grepcode
- http://www.androidcodesearch.com/ androidcodesearch
- http://www.krugle.org/ krugle
- https://github.com/search github code search
- google code search(失效了,记录一下)