- [Thruk](https://www.thruk.org/) - Multibackend monitoring web interface with support for Naemon, Nagios, Icinga and Shinken. ([Source Code](https://github.com/sni/Thruk)) `GPL-1.0``Perl`
- [Uptime Kuma](https://uptime.kuma.pet/) - Modern, self-hosted monitoring tool with a clean UI and rich notification support. ([Source Code](https://github.com/louislam/uptime-kuma)) `MIT``NodeJS`
- [Wazuh](https://wazuh.com/) - Unified XDR and SIEM protection for endpoints and cloud workloads. ([Source Code](https://github.com/wazuh/wazuh)) `GPL-2.0``C`
- [xymon](https://xymon.sourceforge.io/) - Monitoring tool for servers and networks. ([Source_Code](https://sourceforge.net/p/xymon/code/HEAD/tree/)) `GPL-2.0``Perl/C/Shell`
- [Zabbix](https://www.zabbix.com/) - Enterprise-class software for monitoring of networks and applications. ([Source Code](https://git.zabbix.com/projects/ZBX/repos/zabbix/browse)) `GPL-2.0``C`