Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
VenueScanner - Connecting event organisers with venue hosts
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.
Tagvenue - Online venue hire marketplace with a difference. Get together in the right venue.
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
ogaVenue - Find and Book event venues online