Icinga
Icinga monitors availability and performance, gives you simple access to relevant data and raises alerts to keep you in the loop.
- Snippet from Wikipedia: Icinga
Icinga is an open-source computer system and network monitoring application. It was created as a fork of the Nagios system monitoring application in 2009.
Icinga tries to improve Nagios' development process as well as adding new features such as a modern Web 2.0 style user interface, additional database connectors (for MySQL, Oracle, and PostgreSQL), and a REST API that lets administrators integrate numerous extensions without complicated modification of the Icinga core.
The first stable version, 1.0, was released in December 2009, and new versions were released every couple of months as of January 2010.
In 2012, development of a new core component was started and released in 2014 as Icinga 2 to allow for profound architectural changes compared to the Nagios core.