NationBuilder - The world's first platform for leaders, handcrafted from scratch to help you grow your community and lead them to action.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Crowded Communities - The all-in-one community platform.
KanbanFlow - KanbanFlow is a Lean project management tool allowing real-time collaboration between team members. Supports the Pomodoro technique for time tracking.
Ning - Ning is the social platform for the worlds interests and passions online.
Meistertask - MeisterTask is an intuitive task management and collaboration tool.