Sonic 3 Rsdk [ GENUINE » ]
If one plays Sonic 3 via the Retro Engine (either the decompiled version or modded prototypes), it offers features impossible in the original Genesis/Mega Drive ROM:
The core of the engine is the .rsdk file (Retro Engine Data Kernel). This file acts as a virtual filesystem. Sonic 3 Rsdk
The existence of Sonic 3 RSDK walks a fine line. Unlike a traditional ROM hack that runs on an emulator, A.I.R. requires the official RSDK runtime and assets. Furthermore, to use it, you must extract the data from a legally obtained Sonic 3 & Knuckles ROM (usually the Steam version). If one plays Sonic 3 via the Retro
Sega has historically been litigious with fan games (see Streets of Rage Remake), but Sonic 3 RSDK has survived for years. Why? Two reasons: The core of the engine is the
It is a cold, corporate détente. Sega looks the other way, and the fans preserve a masterpiece.

