BuiltWith - Find out the technology behind websites

Interface Index - The «Interface Index» is a 🏷 collection of UI elements from great B2B, SaaS and desktop applications and services – such as GitHub, Mailchimp or Loom.You can use it to 🏎 speed up your interface research or as 👩‍🎨 visual inspiration.

Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.

patool - patool is a portable command line archive file manager

WhatRuns - Extension that helps you identify technologies used on any website at the click of a button.

atool - atool is a script for managing file archives of various types (tar, tar+gzip, zip etc)