Open Ps2 Loader (opl) -

If you have a "Fat" PS2, buy a network adapter and an IDE/SATA hard drive immediately. If you have a "Slim" PS2, use USB (for patience) or set up SMB networking. OPL is the definitive way to experience the PlayStation 2 library in the modern era.

Open PS2 Loader (OPL) is a homebrew application loader that loads PS2 games and applications from digital devices. ConsoleMods Wiki open ps2 loader (opl)

The PS2’s IOP (Input/Output Processor) is essentially a modified PS1 CPU. OPL patches the IOP’s CD/DVD driver routines in memory to redirect reads to Ethernet, USB, or HDD — all while keeping game code untouched. That’s why compatibility is so high (~90–95% of the library). If you have a "Fat" PS2, buy a

It is the evolution of older, now-defunct projects like HD Loader and USB Advance, surpassing them in compatibility, speed, and features. Open PS2 Loader (OPL) is a homebrew application

Modern versions of OPL, such as the 1.2.0 beta builds, have significantly expanded what the classic console can do: Open PS2 Loader (OPL) - ConsoleMods Wiki