Awesome GitHub Topics - Top 500 topics on GitHub that's filtered and categorized
BuiltWith - Find out the technology behind websites
Dense Discovery - A weekly newsletter for discerning web workers
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
AwesomeDigest - An email newsletter for every "awesome" list on GitHub 😻
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.