Nagios Core vs OpenNMS Horizon
A side-by-side comparison of two self-hosted monitoring & status options — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
Nagios Core
Industry classic host and service monitoring engine
VS
OpenNMS Horizon
Enterprise network management and monitoring platform
| Feature | Nagios Core | OpenNMS Horizon |
|---|---|---|
| Category | Monitoring & Status | Monitoring & Status |
| License | GPL-2.0 | AGPL-3.0 |
| Language | C | Java |
| Setup difficulty | Hard | Hard |
| Min. RAM | 512 MB | 4,096 MB |
| Deployment | bare-metal, docker, source | docker, bare-metal |
| GitHub stars | ★ 2,037 | ★ 1,168 |
| First released | 1999 | 2000 |
| Replaces | SolarWinds, PRTG | SolarWinds, PRTG |
Why pick each one
Choose OpenNMS Horizon if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (1.2k GitHub stars)
- Written in Java
Frequently asked questions
Is Nagios Core or OpenNMS Horizon better?
Neither is universally better. Nagios Core has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Nagios Core and OpenNMS Horizon free and open-source?
Yes. Nagios Core is licensed under GPL-2.0 and OpenNMS Horizon under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Nagios Core and OpenNMS Horizon with Docker?
Nagios Core: yes. OpenNMS Horizon: yes.