Fans have managed to reverse-engineer the source code for both Grand Theft Auto Vice City and Grand Theft Auto III.
Did someone say GTA: Vice City Switch port?
Files of two older, but still popular games from the legendary GTA series, GTA Vice City and GTA 3, are now available for download. That means that modders will be able to create potentially new and interesting stuff. And this also means easier porting to other platforms. While it most certainly won’t be able to run on as many devices as Doom,, the team that did reverse-engineering have already got the code running on Switch, Vita and Wii U. They also hope that they’ll manage to get it to work on PS2 and Xbox as well.
Some popular old games have already been reverse-engineered, possibly the most famous example being Nintendo’s 1996 classic Mario 64. That particular classic has been legitimately (but unofficially, of course) ported to PC with zero emulation involved. The difference is that, with emulation, PC runs code pretending to be another device, most often console. But by using source codes one can rebuild the game from the ground up specifically for the PC. Such a game doesn’t only run like almost perfectly, but even supports various mods, which couldn’t be implemented before.
Source: Kotaku.com