BuiltWith - Find out the technology behind websites
Revionics - Revionics offers lifecycle price, promotion and markdown optimization solutions for the retail industry.
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Competera - Competera is a price tracking tool for performance-oriented eCommerce retail and brands of all sizes worldwide.
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.
VReprice - VReprice is a legit repricing optimization software that automates pricing and detailed analysis to enhance profitability.