Ever since The_Flow revealed the work he has been doing on the Blu Ray drive on the PS4, people seem to have caught onto this thing called BDJ or Blu Ray Java.
BDJ has been around for a long time, going back to the early days of the PS3 scene, before the console was hacked, users realised they could make their own homebrew games to run off a Blu Ray disc, prolific PSP developer FreePlayPSP released an SDK to help people create homebrew, it was even possible to run this homebrew off a Thumb Drive, though Sony managed to patch that up, which meant that the homebrew could only be ran via disc, back in those days Blu Ray discs were quite expensive and not everyone was interested in this way to run homebrew.
There was one developer who always stuck with Blu Ray Java, he founded a company called LuBlu Entertainment and has made a few nice games for Blu Ray Java, he even gave a new name to BDJ and that is Blu-Play.
You can find his games and website here:
BDJ Homebrew can be run on anything with a Blu Ray drive, it can be run on your PS3, PS4 and PS5 without any modding.