Demandbase - Bizo
Clearbit - Clearbit provides Business Intelligence APIs
6sense - 6sense is a B2B predictive intelligence engine for marketing and sales.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
Metadata - Metadata automates account based demand generation for B2B companies using AI, data enrichment, & targeted advertising.
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.