Nagios has been around for quite some time, but producing output it can consume is something of a black art. Only the plugin documentation actually explains what all the extra semicolons or extended formatting even mean. This is especially onerous when performance consuming add-ons expect a specific structure before operating properly. The NagAconda package strives to greatly simplify the process of actually generating Nagios output using Python.
openpom is a Web interface based on NDO for Nagios or Icinga. It allows you to view almost everything about Nagios or Icinga in a single page: alert, ack, downtime, comment. You can also interact with Nagios or Icinga through ack, downtime, comment, disable, and reset buttons. You can filter on hosts and services states (such as critical, warning, unknown, ok, or outage). The status popin allows you to display graphs, either the ones from Nagios (trends.cgi) or custom ones based on RRD (such as pnp4nagios).
NS4300N Nagios Utils is a collection of tools for working with the Promise NS4300N NAS within the Nagios framework. The two current tools allow for monitoring the chassis and remotely shutting down the system. Future versions of this utility set will include the ability to monitor drives and volumes.
Panoptes is a scalable, extensible network and host monitoring tool. It includes a dynamic Web management interface based on the Dojo toolkit. It monitors SNMP, TCP port availability, ICMP, HTTP response and content, and SSL certificates internally. It supports monitoring anything else via shell scripts. It also includes a packet capture tool for discovery of hosts, port, and OS.
jmxtrans is effectively the missing connector between JMX and whatever logging or graphing package that you can dream up. jmxtrans is very powerful tool that reads JSON configuration files specifying servers/ports and JMX domains/attributes and then outputs the data in whatever format you want via special "Writer" objects that you can code up yourself. It does this with a very efficient engine design that will scale to querying literally thousands of machines. The core engine is pretty solid and writers are included for cacti/rrdtool, graphite, and stdout.
DaVINCI is a dashboard builder and editor for Nagios systems. It can be used to add advanced visualization functionalities for Nagios-based management applications. Its editor uses a drag and drop interface to allow users get monitoring indicators and information directly from their databases and show them in a graphical and animated dashboard, without having to write a single line of code.