OpenGrok - OpenGrok is a fast and usable source code search and cross reference engine.
GrepCode - GrepCode.com is a code search engine built by developers for developers to search and browse open...
Insight.io - Best web-based IDE-like source code browsing and search tool
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+.
Open HUB - Open HUB is an open source directory that anyone can edit.
Etsy Hound - Hound is an extremely fast source code search engine.