Nagios Plug-In Development

The easy and most supported languages are Perl and C++, however it is not hard to write a plugin with another language, however doing it well and properly takes a bit more effort. The Nagios Plugin API is well worth reading, in detail.

Guidelines

The Nagios Plugin Development Guidelines are clearly the best place to start when investigating writing your own plug-in. They are also useful when reviewing one and seeing if you want to use it.

Java Plugins

It would seem that JNRPE – Welcome to the JNRPE package is well worth a look. The idea here is to prevent NRPE starting a JVM for every check, which is good. See Creating Nagios Plugins with Java for more details on this.