It's been more than 20 years since Sega first used the GD-rom format, so seems like it would be out of patent now? Or are there other legal issues that prevent the release of GD media into the public domain? I know it would only be of niche interest, but couldn't someone now release a disc drive for PC that reads GD discs? It's not really anything that special, isn't it just a regular disc with tracks more tightly packed than a CD-rom but not as tight as a DVD, so you'd just need to calibrate the drive to the GD spec? I suppose you could even go so far as to produce recordable GD discs, but maybe that's a step too far in terms of profitably (too niche to justify mass production).