Sticky Tickets
attending.io
Eventbrite
Alf.io
Attendize Event Ticketing
Confetti
EventCreate
pretix
DownToMeet
Meetup
Google Groups
Eventbrite
Bigtent
Facebook Local
Mobilizon
Mighty Networks
Sticky Tickets DownToMeetattending.io - Tiny event pages to ask people one question – are you attending? Twitter login.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.
Alf.io - Looking for a solid open source alternative to EventBrite or MeetUp? Discover Alf.io! Keep control your event and your data with Alf.io. Get started today!
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform