LibreNMS is described as 'Autodiscovering PHP/MySQL based network monitoring system forked from Observium. LibreNMS aims to be easy to use, painless to deploy, and support monitoring of a wide range of devices. Observium's license changed to a modified QPL license in May 2012, and' and is a Network Monitor in the network & admin category. There are more than 25 alternatives to LibreNMS for a variety of platforms, including Linux, Windows, Web-based, Android and Self-Hosted apps. The best LibreNMS alternative is Zabbix, which is both free and Open Source. Other great apps like LibreNMS are Nagios, Paessler PRTG Network Monitor, Spiceworks and ManageEngine OpManager.
LibreNMS is a remake of Observium