Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Support Hero - Educate your customers through self-help support
BuiltWith - Find out the technology behind websites
WhatRuns - Extension that helps you identify technologies used on any website at the click of a button.
DataBasic - Easy-to-use web tools for beginners
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.