Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Zoho Backstage - Plan, run, and analyze your event— all from one place
Bylde - Bylde is a SaaS platform you can use to Start, Manage and Grow your groups and communities.
Meetup for iOS and Android - Discover groups that are all about the things you love