NetXMS 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.
| Feature | NetXMS | OpenNMS Horizon |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 78 · Good | 83 · Excellent |
| 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 | docker, bare-metal | docker, bare-metal |
| GitHub stars | ★ 403 | ★ 1,173 |
| First released | 2004 | 2000 |
| Replaces | SolarWinds, PRTG | SolarWinds, PRTG |
What are NetXMS and OpenNMS Horizon?
NetXMS
NetXMS is an open-source network and infrastructure monitoring system with auto-discovery, event correlation, and a flexible alerting engine. It scales from small networks to large distributed environments.
- Network auto-discovery
- Event correlation
- Distributed monitoring
- SNMP and agent support
OpenNMS Horizon
OpenNMS Horizon is an enterprise-grade network monitoring and management platform that handles fault, performance, and traffic monitoring at scale. It supports SNMP, flow analysis, and event correlation.
- Fault and performance monitoring
- Flow analysis
- Event correlation
- Scales to large networks
NetXMS vs OpenNMS Horizon: key differences
NetXMS is written in C++, while OpenNMS Horizon is built with Java. Licensing differs — GPL-2.0 for NetXMS versus AGPL-3.0 for OpenNMS Horizon. NetXMS is the lighter option, starting around 512 MB of RAM against 4,096 MB for OpenNMS Horizon. OpenNMS Horizon is the more established project (first released 2000), while NetXMS arrived in 2004. OpenNMS Horizon has the considerably larger community, at 1,173 GitHub stars versus 403.
Why pick each one
Choose NetXMS if…
- Powerful event processing
- Scales to large networks
Watch out for
- Steep learning curve
- Desktop console for full features
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 NetXMS or OpenNMS Horizon better?
Neither is universally better. OpenNMS Horizon has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are NetXMS and OpenNMS Horizon free and open-source?
Yes. NetXMS 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 NetXMS and OpenNMS Horizon with Docker?
NetXMS: yes. OpenNMS Horizon: yes.
Which is lighter on resources, NetXMS or OpenNMS Horizon?
NetXMS has the smaller minimum footprint at 512 MB of RAM, compared to about 4,096 MB for OpenNMS Horizon. Real-world usage depends on library size, user count, and enabled features.