Messaging Peer is a service that runs on your Windows computer. It allows a publicly-accessible (hosted) Linux server running PHP 5 or higher to make function calls against a Windows server that is behind a firewall, and not accessible from the public internet. It is ideally suited for situations where you want to deliver output from Windows applications from a Linux server and/or you need full control of the machine running the target code. The Windows machine remains hidden from public access.