Open PS2 Loader, or OPL as it is popularly known, lets you play games over the network, via USB or even through an internal hard drive on the Playstation 2. This is very useful when you don't have a reader, for example.
This application must be configured on a console memory card to be used on the console.
The OPL supports three categories of devices: USB and SMB shares, these two support USBExtreme and .ISO formats and the Playstation 2 hard disk, in the FAT version that supports the HDLoader format.