Zabbix

Zabbix is a world-class, open-source monitoring platform that offers unparalleled scalability. It is capable of monitoring millions of metrics from hundreds of thousands of devices simultaneously. Zabbix supports both agentless (SNMP, ICMP) and agent-based data collection. Its flexibility is its greatest strength, allowing users to build complex, multi-level triggers and custom visualization templates. Because it is free to use, it is the primary choice for technical teams that want full control over their monitoring stack without recurring licensing fees.