Nagstamon is a Nagios status monitor for the desktop. It connects to multiple monitoring servers such as Nagios, Icinga, Opsview, Centreon, Op5 Monitor/Ninja and Check_MK Multisite. It resides in the system tray or as a floating status bar, displaying a summary of hosts and services in a critical, warning, unknown, unreachable or down state. Hovering the mouse over it reveals a detailed status overview. Connection to the displayed hosts and services is established from the context menu via SSH, RDP and VNC. Users can receive sound notifications. Hosts and services can be filtered by category and regular expressions.