This is a loadable extension for PHP running on Windows implementing serial port handling and communications. Once installed in PHP environment you can programm PHP applications to control serial device hosted on server from remote location; these devices can be anything from video switcher, cameras pan/tilt, ham radios, media players, home automation boxes, GSM modems/terminals (send/receive SMS), only your imagination and needs are the limits.
There are available functions for opening, closing port, checking port state, reading / writing from / to port, setting control lines.