OpenGrok - OpenGrok is a fast and usable source code search and cross reference engine.
searchcode - A source code search engine
GrepCode - GrepCode.com is a code search engine built by developers for developers to search and browse open...
CRX Extractor - Get any Chrome Extension source code. Learn and hack!
Krugle - Krugle is the complete enterprise solution for search targeted to the development organization.
Binocs - Uptime Monitoring for the web in your command line