Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Splash - Anyone can create a Splash event, whether you're a company hosting a single event or an individual hosting a personal event like a birthday or wedding. Get Started for Free. Text goes here. X. Full Event Program.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.
Prometheus - An open-source systems monitoring and alerting toolkit.