LibreNMS forked from the last GPL-licensed Observium revision, but the project says the split was driven by different priorities and values and a desire for a community-based project.
LibreNMS is a PHP/MySQL-based network monitoring system using SNMP, LLDP, CDP, and other protocols for autodiscovery. It supports thousands of device types, provides alerting, graphing (via RRDtool or InfluxDB), API access, and integrates with tools like Oxidized for configuration management and Smokeping for latency monitoring.
Observium was a popular network monitoring platform created by Adam Armstrong, built on PHP and MySQL with auto-discovery capabilities that made it a favorite among network administrators. It was originally released under the GPL, which meant anyone could use, modify, and redistribute it freely. But in 2012, the licensing situation changed.
After May 29, 2012, Observium adopted a license that was incompatible with the GPLv3. The project moved toward a dual-licensing model with a free "Community Edition" and a paid "Professional Edition" with additional features. For contributors who had submitted code under the GPL expecting it to remain free, this felt like a bait-and-switch.
In October 2013, Paul Gear and other community members forked the last GPL-licensed version of Observium (SVN revision 3250) and created LibreNMS. The fork was explicitly positioned as the community-driven, fully open-source alternative — GPL-licensed, welcoming contributions, and committed to keeping all features free. The name followed the "Libre" convention popularized by LibreOffice and other freedom-focused forks.
LibreNMS grew rapidly. The community-driven development model meant features were added faster, bugs were fixed more quickly, and the project attracted a much larger contributor base than Observium's more controlled development could sustain. By the mid-2010s, LibreNMS had surpassed Observium in most metrics: more supported devices, more contributors, more frequent releases, and broader adoption.
Today LibreNMS has over 480 contributors, 14,000+ commits, and supports thousands of device types. Organizations like the Wikimedia Foundation run LibreNMS in production. The project exemplifies how a licensing change that alienates contributors can inadvertently create a more successful competitor.
Adam Armstrong creates Observium as a GPL-licensed network monitoring platform
Observium changes to a license incompatible with GPLv3; introduces dual Community/Professional model
LibreNMS forked from the last GPL-licensed Observium revision (SVN r3250)
LibreNMS surpasses Observium in community size and feature set
LibreNMS reaches 400+ contributors and broad enterprise adoption
LibreNMS demonstrated the power of the GPL's copyleft provisions: when a project built on community GPL contributions changes its license, the community retains the right to fork from the last freely-licensed version. The result was a more vibrant and feature-rich project than the original could sustain under its restricted model.
The fork also reinforced a recurring pattern in open source: projects that restrict contributions or features behind paywalls often lose their contributor base to freer alternatives. Observium continues to exist but with a fraction of LibreNMS's community activity.