Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
RegOnline - Regonline is the leading online event registration, planning and management software.
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
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
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.
Ticket Tribe - Sell tickets online with no fees per ticket