cPanel - With its first-class support and rich feature set, cPanel & WHM has been the web hosting industry's most reliable, intuitive control panel since 1997.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Plesk - Plesk puts all the automation, security, and technical tools an IT professional needs in one simple and easy to use dashboard.
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.
Sentora - Sentora is an open-source web hosting control panel built specifically to work on a variety of Linux distributions. Sentora is licensed under the GPL and is a separately maintained fork of the original ZPanel project.
Prometheus - An open-source systems monitoring and alerting toolkit.