BuiltWith - Find out the technology behind websites
Awesome GitHub Topics - Top 500 topics on GitHub that's filtered and categorized
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Dense Discovery - A weekly newsletter for discerning web workers
WhatRuns - Extension that helps you identify technologies used on any website at the click of a button.
AwesomeDigest - An email newsletter for every "awesome" list on GitHub 😻