NationBuilder - The world's first platform for leaders, handcrafted from scratch to help you grow your community and lead them to action.
Golden Volunteer App - Golden is no ordinary community service app or volunteers app. Create Golden Moments by searching volunteer opportunities. Go from Volunteering to Volunteered.
Crowded Communities - The all-in-one community platform.
HelpStay - HelpStay Exchange
Ning - Ning is the social platform for the worlds interests and passions online.
Idealist - Volunteer, work, and intern job search