German agent- and SNMP-based infrastructure monitoring platform with a free open-source Community edition.

Checkmk is an infrastructure and application monitoring tool developed by Checkmk GmbH, headquartered in Munich, Germany. The software itself dates back to 2008, when it was created in Munich.

It monitors servers, network devices and applications using both native agents (for Windows, Linux and Unix) and agentless methods like SNMP, IPMI and API-based checks, built on a Nagios-derived core. The free, GPL-licensed Community edition is unrestricted in host count, while paid Pro and cloud-hosted editions add a faster “Micro Core” engine, automation for agent updates, and enterprise reporting.

In 2025 the company took a strategic growth investment while keeping its German headquarters and open-source core.