Based on an idea he has had since he was a child, security software technician CTurt has developed a way for people to play unofficial games on a PS2 console by burning them to a DVD along with an exploit.
If you don’t have a very technical explanation of how it works, check out the CTurt blog post. If you only want the tl version; dr basically created a way of “by exploiting the functionality of the console’s DVD player “triggering damage to video playback and then running a game through the resulting blown hole in the copy protection system.
Because it’s important? Because all you have to do is insert a disc, in the same way you would have launched any other PS2 game. You don’t need to get a chip mod, you don’t need a special USB exploit, just insert the disc and play a new code without changing anything else on the console.
The CTurt blog post does everything to emphasize the word “homebrew”, but if you were wondering about other direct applications for this exploit, two of his demo videos show a PS2 with an SNES emulator and a “backup” copy of The shadow of the colossus.
While this clearly works on a PS2, CTurt theorizes that the same exploit (or at least the same principle) could work on anything from a PS1 to a PS4.