This is a repackaged open source software product wherein additional charges apply for support and pre-installed MySQL database ready to install out of the box.
Nagios is an open-source monitoring system for computer systems. It was basically designed to run on the Linux operating system and can monitor devices running Linux, Windows, and Unix Operating Systems.

Features:
Server Monitoring
Nagios is best known for being a great server monitoring software in the market. Server monitoring is made very effective in Nagios because of the flexibility for monitoring your servers with both agent-based and agentless monitoring.

Application Monitoring
Employing effective application monitoring with Nagios enables your firm to quickly detect application, service, or process issues and take immediate action to eradicate downtime for your application users. Nagios offers tools for application monitoring and application state including Windows applications, UNIX applications, Linux applications, and other web applications.