How it plugs in
—Public API
NoOpen source
YesFree tier
Signal on Server Monitoring5.8#29 of 38
Nagios Core monitors IT infrastructure including servers, network devices, websites, applications, services, and custom metrics.

Pricing
- Nagios CoreNo node limitations · Open source under GPL v2 · Manual text-file configurationFree
As nagios.org lists them, checked 4 Oct 2026.
Near it
All alternatives →- L
LogicMonitor#28 on this board - FFrameFlow#30 on this board
- EEeG Enterprise#27 on this board
- OCOpsview Cloud#31 on this board
- Z
Zabbix#26 on this board - SS
SolarWinds Server & Application Monitor#32 on this board - NNaemon#25 on this board
- SAServers Alive#33 on this board
- MMonit#24 on this board
- PFPandora FMS#34 on this board