This library is intended to control a LED device plugged on parallel port.
A such device is composed of a number of LED (default is 8, maybe more is possible, I don't know) plugged on parallel port.

Download
You can download from the Git repository.
Example
Here is an example from Giorgio Luparia: ledcontrol.c
Video
Giorgio Luparia made 2 videos of what you can do with libparportled: