Winrpe is a Nagios NRPE implementation for Windows systems. It is a packaging of Nagios NRPE addon, Xinet, Cygwin and a collection of windows specific NRPE plugins for monitoring cpu, disk, memory, eventlog, services and performance counters. It can easily be expanded by other plugins.
The Nagios NRPE addon allows you to execute Nagios plugins on remote machines, enabling you to monitor local resources like CPU load, memory and disk usage. Since these resources are not usually exposed to other machines, an agent like Winrpe must be installed on the remote Windows machines. Xinetd is an open source super server daemon, which features a variety of access control (tcp wrappers) and configuration mechanisms (time and connection limits) and extensive logging. Cygwin is a Linux-like environment for Windows. It consists of a DLL (cygwin1.dll), which emulates substantial Linux API functionality, and a collection of tools.