ActivePrime - ActivePrime platforms provide data enrichment solutions for CRM systems.
Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.
Salesforce Data.com - Data.com provides company profiles and contact information across millions of businesses worldwide.
BuiltWith - Find out the technology behind websites
Lead Peep - Thousands of b2b leads in the palm of your hands, instantly.
What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.