Awesome GitHub Topics - Top 500 topics on GitHub that's filtered and categorized
BuiltWith - Find out the technology behind websites
git:logs - The definitive list of open source resources on Github
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Mailbrew - Automated email digests from Twitter, Reddit, YouTube & more
WhatRuns - Extension that helps you identify technologies used on any website at the click of a button.