PlayStation 2 can play homebrew games by using DVD player exploits – Engadget

You just need to put a disc in the PS2s drive and wait for it to load. You can even boot into a menu to choose from numerous video games kept on a single disc. That may not be an option for long when some PS5 designs wont consist of disc drives, but it does raise hope for those desiring to expand their video game collections with informal titles.