For the (for a CD case):
Some developers create "custom PKGs" where they package an emulator and a specific game (like Mario Kart 64) into a single installer. This makes the game appear directly on your XMB (main menu) as if it were a native PSN title. mario kart 64 pkg ps3 new
For most casual players, the is the better option. It requires zero tweaking after installation. For the (for a CD case): Some developers