Jostle - A new kind of employee intranet that drives engagement & workplace culture. Achieves social participation in work relevant way. Participation rates are over 85%.

EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.

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!

Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.

MangoApps - Founded in 2007, MangoSpring transforms the way teams work together.

Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.