Sourcegraph - Sourcegraph is a free, self-hosted code search and intelligence server that helps developers find, review, understand, and debug code. Use it with any Git code host for teams from 1 to 10,000+.
openDesktop.org - The website openDesktop.
OpenGrok - OpenGrok is a fast and usable source code search and cross reference engine.
OSOR - OSOR is the Open Source Observatory, a project to provide a framework for developing and executing autonomous observations.
GrepCode - GrepCode.com is a code search engine built by developers for developers to search and browse open...
SourceForge - The Complete Open-Source and Business Software Platform.