Elucify - A completely free software tool that uses crowdsourced data to find business email addresses
6sense - 6sense is a B2B predictive intelligence engine for marketing and sales.
Lead Forensics - B2B website analytics and lead generation.
Leadiro - Seriously Smart & Live B2B Data
KiteDesk - Use KiteDesk sales prospecting software to generate leads from our premium data marketplace. Then reach prospects and build a sales pipeline with organized Lead Lists. Syncs direct with CRM too!
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.