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

DownToMeet - DownToMeet is a platform to organize, find, and attend group events.

Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform

Far or Near - Far or Near™ is a privacy-oriented social network that helps you connect with others who share your...

pretix - pretix helps you to sell tickets for your event in an easy way. It supports multi-lingual events and provides a wide range of features