SalesLoft - The simpliest way to build the most accurate and targeted lists of leads on the internet
Clearbit - Clearbit provides Business Intelligence APIs
Outreach - Outreach Is Your Sales Communication Platform
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
Yesware - Sell smarter with email tracking and more
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.