Adagios is a Web-based Nagios configuration interface built to be simple and intuitive in design, exposing less of the clutter under the hood of Nagios. It has a REST interface for both status and configuration data as well a feature complete status interface that can be used as an alternative to the Nagios Web interface.
Check_MK is a complex addon for Nagios/Icinga and consists of three subprojects. The check and inventory system Check_MK is a general purpose Nagios plugin for retrieving data. It adopts a new approach for collecting data and obsoletes NRPE, check_by_ssh, NSClient, and check_snmp. It features a significant reduction of CPU use on the Nagios host and automatic inventory of items to be checked, and is especially useful with larger Nagios installations. "MK Livestatus" gives immediate and fast access to live and historic Nagios status data. It's a supported backend for many addons including NagVis, NagiosBP, and Thruk. "Check_MK Multisite" is a feature complete replacement for the Nagios GUI, and uses MK Livestatus as a backend. It is very fast, and supports efficient distributed monitoring.
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.
Monitoring::Spooler is a handy queue manager for queueing and delivery of monitoring notifications. It is able to handle several groups of on-call personnel and provides an extensible plugin mechanism to connect it to virtually any remote service which provides some kind of API. It is designed to work nicely with App::Standby.
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.
Nagios 4 iPhone is a Nagios interface for the iPhone. It does not require any modifications on your Nagios servers. The server part of this software collects statistics on several Nagios servers, serves a few static files, and generates a JSON response. The client part handles the display of the data on the iPhone.
The Ninja project is an attempt to develop an alternative Nagios GUI with the aim of being the most useful Open Source Web front end for Nagios. It improves searching and filtering and scalability. It supports templates and skins for customizing appearance, and supports several databases. You can use the components of Ninja in combination with the CGI scripts of the original Nagios Web GUI or as replacements for them.