Tuio - Tuio is a billing and payment application that allow daycare centers and pre-schools to centralize and manage all parent billing and payment in one place.
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Sawyer - Discover a wonder-filled world of kids classes, camps, events, and activities, right in your neighborhood
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Yusp - Yusp is a next generation, real-time personalization engine having all product modules as defined by Gartner for various business models.
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