BuiltWith - Find out the technology behind websites
Apify - Apify is a web scraping and automation platform that can turn any website into an API.
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Scrapy - Scrapy | A Fast and Powerful Scraping and Web Crawling Framework
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.
Portia - An open-source visual scraping tool that lets you scrape the web without coding, built by Scrapy...