Icinga is described as 'Fork of Nagios and is backward compatible. So, Nagios configurations, plugins and addons can all be used with Icinga. Though Icinga retains all the existing features of its predecessor, it builds on them to add many long awaited patches and features requested by the' and is a Network Monitor in the network & admin category. There are more than 50 alternatives to Icinga for a variety of platforms, including Linux, Windows, Web-based, SaaS and Self-Hosted apps. The best Icinga alternative is Zabbix, which is both free and Open Source. Other great apps like Icinga are Nagios, Datadog, Beszel and HyperDX.