What are some alternatives?
When comparing eZ Server Monitor and Cloudradar, you can also consider the following products
PhpSysInfo - phpSysInfo is a customizable PHP script that displays information about your systems.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
netdata - Real-time performance monitoring, done right
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.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Icinga - Icinga is a fork of Nagios and is backward compatible.