Nagios is an application, system and network monitoring application. It can escalate problems by email, pager or any other medium. It is also useful for incident or SLA reporting. Nagios is written in C and is designed as a background process, intermittently running checks on various services that you specify. The actual service checks are performed by separate "plugin" programs which return the status of the checks to Nagios. The plugins are located in the nagios-plugins package.Latest release: 2.0-2