Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Mixily - Hosting your event just got easier.
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
EvePlaner - EvePlaner.net lets you create and manage your events the easiest way possible.
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
Nusii - Collect content & files from busy clients