Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Online-RSVP.com - Beautiful online RSVP for wedding & other events. Create an online invitation, track your guests responses.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
RSVPify - A powerful and awesomely customizable platform for selling tickets online for your event.
Odoo - An all-integrated business app suite to unleash your growth potential.
Naologic - Speed up collaboration and work more securely with your partners, customers, and vendors by creating custom apps without a development team.