Watching the “Network Monitoring Application of the Year” vote on http://www.linuxquestions.org I have noticed a new Nagios / competitor: Shinken. The name describes a very sharp Japanese sword – associating the program with its large scale monitoring capabilities.
The software it’s written in Python and it’s compatible with the Nagios configuration. Also they say that they use fewer resources than the Nagios counterpart. The developer has put an accent on the Business rules, Cloud computing and “Very large monitoring capabilities”. Take a look at their features: http://www.shinken-monitoring.org/features/
You can find a quick compare between the two programs: http://www.shinken-monitoring.org/what-is-in-shinken-not-in-nagios-and-vice-versa/
Try it yourself by heading to the download section were you will find a preinstalled VM, the sources (no compile requested!) & the .deb package
It’s an early, but promising, start as the software is still at the version 0.5.