Salesforce Data.com - Data.com provides company profiles and contact information across millions of businesses worldwide.
Clearbit - Clearbit provides Business Intelligence APIs
MailGet Enricher - MailGet Enricher is a lead enrichment software which transforms any email address into complete person’s profile.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
ActivePrime - ActivePrime platforms provide data enrichment solutions for CRM systems.
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.