Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Cvent - Cvent's event management software provides event planners with a complete solution to increase event attendance and decrease event costs.
Event Hunt - Startups and Tech Events Curated By Locals
EventMobi - EventMobi is an interactive mobile event app, audience response and engagement platform for conferences and trade shows.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Mobilizon - A free and federated tool to get our events off Facebook