Nagios has been around since 1999 and is extremely battle-tested. The UI is from that era too, and configuration is still text files.
| Dimension | monsys.ai | Nagios |
|---|---|---|
| Configuration | ✓Web dashboard, REST API, signup → working | ~.cfg files in /etc/nagios: works, but for specialists |
| Modern UX | ✓Next.js dashboard, dark mode, mobile responsive, NL/FR/EN | ✗Perl/CGI UI from 2002 |
| Multi-tenant | ✓Postgres RLS: strictly separated tenants | ✗Single-tenant: multiple customers = multiple installs |
| AI explain / context | ✓Local llama3.1 for log explanation | ✗Not available |
| CVE matching | ✓NVD + OSV + EPSS, built in | ✗Not available |
| Compliance evidence | ✓ISO/NIS2/CyFun mapping native | ✗Not available |
| Plugin ecosystem | ~Fixed set of Linux/Windows collectors, no external plugins | ✓Hundreds of Nagios plugins for exotic hardware/software |
| Resource usage | ✓Hub: 4 vCPU/4 GB for < 50 hosts | ✓Famously light: runs on 1 vCPU for 100 hosts |
Nagios Core is free and proven stable since 1999. For very minimal, low-resource setups it remains a valid choice. monsys is a 2026 product with different priorities.
Guides that solve everything by hand first, and only then show what monsys automates.