Yammer

Yammer (www.yammer.com) is a best-in-class Enterprise Social Network used by more than 200,000 organizations worldwide - including approximately 85 percent of the Fortune 500 - to foster team collaboration, empower employees, drive business agility and promote organizational connectedness. Yammer's freemium business model lets customers see the value of Yammer before upgrading to the premium offering. Founded in 2008, Yammer is now part of the Microsoft Office Division.