Vendor lineage
Nagios - NetSaint, Nagios Core and Nagios Enterprises
Ethan Galstad's NetSaint of 1999 became Nagios in 2002 and a St. Paul company in 2007; its plugin model shaped a generation of monitoring.
Nagios is an open source network and infrastructure monitoring system that watches hosts, services and network devices and alerts when they fail and again when they recover. Ethan Galstad released it as NetSaint 0.0.1 on 14 March 1999 and renamed it Nagios in 2002 after the owners of a similarly named trademark raised a legal challenge; the new name is a recursive acronym, Nagios Ain't Gonna Insist On Sainthood, and 'agios' is the Greek for saint. Galstad founded Nagios Enterprises in 2007 in St. Paul, Minnesota, to provide commercial support and the proprietary Nagios XI.
The design is the thing to understand. Nagios Core does no monitoring itself: it schedules external programs, the plugins, each of which tests one service or resource and returns a status code, 0 for OK, 1 for warning, 2 for critical, 3 for unknown. Hundreds of community plugins exist, and that architecture is why the system spread: anybody who could write a script could monitor anything. Written in C, licensed under the GPLv2, it runs on Linux and other Unix systems.
Versions marked the arc: 2.0 in February 2006 with the Event Broker API, 3.0 in March 2008, 4.0 in September 2013 with worker processes for parallel checks. The commercial company's products are Nagios XI, Core, Log Server, Network Analyzer and Fusion.
The forks are part of the record too. In May 2009 a group of community developers forked Nagios as Icinga, citing slow development and insufficient response to patches; Icinga 2 in 2014 was a ground-up rewrite. On 16 January 2014 Nagios Enterprises redirected the nagios-plugins.org domain to a server it controlled without notifying the community plugin team, whose displaced maintainers continued as Monitoring Plugins. Shinken, Naemon and Checkmk are the other derivatives. A project that made monitoring a community craft then had to live with what a community does when it disagrees.
- Wikipedia: Nagios - NetSaint 0.0.1 released 14 March 1999 by Ethan Galstad; renamed Nagios in 2002 after a trademark challenge; the recursive acronym; plugin architecture and status codes; C and GPLv2; Nagios Enterprises founded 2007 with the proprietary Nagios XI; 2.0 February 2006, 3.0 March 2008, 4.0 September 2013; the Icinga fork of May 2009 and Icinga 2 in 2014; the 16 January 2014 nagios-plugins.org redirect and Monitoring Plugins; Shinken, Naemon, Checkmk (read 2026-10-06)
- Nagios - About: 'Nagios began in 1999, when Ethan Galstad developed the open-source Nagios Core engine'; 'Ethan founded Nagios Enterprises in 2007 in St. Paul, Minnesota'; Nagios XI, Core, Log Server, Network Analyzer and Fusion (read 2026-10-06)