LinkedIn Premium - LinkedIn is a social network helping brands and professionals to connect, identify sales prospects, hire talent, and promote their business.
Bitrix24 - Bitrix24 is a free (for small businesses) social enterprise platform. It is a united work space which handles the many aspects of daily operations and tasks. Create your own social intranet in minutes!
Zoho People - Zoho People offers complete online HR solution to manage the workforce.
Workplace by Facebook - Connect everyone in your company and turn ideas into action.
OrangeHRM - Free and Open source HR Software with an array of HR Modules. Personal Information management, Leave Management, Time & Attendance, Performance, Recruitment, On-Boarding and many more.
Salesforce Chatter - Salesforce Chatter provides a suite of collaboration features to any application built on Force.com.