Upsilon is a distributed, flexible, and extensible system monitoring application. Being distributed means you run service checks on Upsilon nodes in your network where it makes sense, either on every server or on a management network, inside or outside the firewall. You can run checks on secure, hard to reach networks, and push those results to a central server. You can optionally execute "agentless" checks just by using SSH. Being flexible means that if you can script it, you can monitor it. Unlike most monitoring systems, the monitoring scripts are external to the main server, so you can use Upsilon to execute your monitoring scripts in an extremely robust way. Upsilon has been used to monitor many different things and is API-compatible with all nagios monitoring scripts. Being extensible means you can add monitoring checks to Upsilon at runtime without needing to restart the server. The upsilon-node and upsilon-web projects both have their own REST APIs.
SysopView shows information in a visually attractive way, like computers in movies do. The idea is that it can show information relevant to system administrators non-comprehensible for non-technical personnel, while still looking attractive even if you don't know what is shown. The current version can show nagios status data, webcam streams (mjpeg, jpeg, and video4Linux), and VNC, has a built-in terminal emulator in which regular text applications can be run, can sniff the network (including remotely) and dissect streams and show pictures which are sniffed, can show external bitmaps (from, for example, mrtg and rrdtool), and can scroll text (currently showing output of rssfeeds).
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).
Opsview Core is a network monitoring software application. It solves the challenges of monitoring modern IT and network systems. It is a drop-in replacement for Nagios Core, with full support for its plugins and 100% compatibility. It is easy to install and configure and is ideal for monitoring applications networks, and Windows, Linux, and Unix servers. VMWare, KVM, Xen, and Microsoft Hyper-V are supported, and Amazon EC2 and other cloud services can be monitored. It works with Opsview Mobile to allow you to monitor your systems on the go.
CoffeeSaint is a Java application that shows the status of Nagios (version 1 up to 3 and the newer XI) on a screen. It can, if there are no errors, display a Webcam feed. If an error status occurs, it can play a sound. One can configure it to display certain errors/warnings always on top. It is remotely configurable via a built-in Web interface.
check_db2_health is a plugin for Nagios that allows you to monitor DB2 database servers. Itcan operate in several modes: measuring how long it takes to connect and log in; display the number of connected users; display percentage of synchronous reads (SRP); display the percentage of asynchronous writes; display hit ratio in Buffer Pools, or only in Data Pages or Index Pages; display the percentage of SELECT that use an index; display the number of deadlocks per second; display the number of lock requests per second that could not be satisfied; display the fraction of time which was spent waiting for locks; display used space in a database or tablespace; display free space in a tablespace (in contrast to the previous mode, you can use units (MB, GB) for the thresholds); or display used space in a database log.
The Merlin project was initially started to create an easy way to set up distributed Nagios installations, allowing Nagios processes to exchange information directly as an alternative to the standard method using NSCA. It has also been extended with fault tolerance, the ability to store status information in a database, and other features. This allows Merlin to function as a backend for applications such as the Ninja project.
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.
Jmx4Perl provides an alternate way of accessing Java JEE Server management interfaces that are based on JMX (Java Management Extensions). It is an agent-based approach where a small Web application deployed on the application server provides HTTP/JSON-based access to JMX MBeans registered within the application server. It is set up from a handful of Perl modules, which can be integrated seamlessly in your own programs. It also includes a Nagios plugin, check_jmx4perl, a jmx4perl command line tool for remote JMX queries and operations, and a readline-based JMX shell j4psh, with context sensitive command completion and syntax highlighting.