Task Scheduler - The Task Scheduler enables you to automatically perform routine tasks on a chosen computer. Task Scheduler does this by monitoring whatever criteria you choose (referred to as triggers) and then executing the tasks when their criteria are met.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets

System Scheduler - System Scheduler for Windows, Free Task Scheduler Software replace Microsoft Windows Task Scheduler

Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform

RoboIntern - An automation and scheduling software with focus on repetitive office tasks.

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