Tealfeed - A knowledge sharing platform to empower creators
BuiltWith - Find out the technology behind websites
Slack - A messaging app for teams who see through the Earth!
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Lunyr - A decentralized crowdsourced encyclopedia.
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.