Best Top 10 open source SIEM solutions 2019

Nagios, Zabbix and SIEMonster

Nagios is another monitoring system that you can use as a SIEM, it is open-source and you can add your own plugins. The same goes for Zabbix.

SIEMonster is build on open source components, but the great part of this project, is the fact that all of the roadmap items are community driven.