VMmanager - VMmanager is a QEMU/KVM server virtualization management software, which presents perfect tools for creating virtual machines, providing VPS services, and building cloud infrastructure.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Virtkick - Virtkick is a Software as a Service VPS control panel and your company’s storefront.
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.
oVirt - oVirt is a virtualization management application.
Prometheus - An open-source systems monitoring and alerting toolkit.