After downloading Re3 SourceNext, follow these steps to install and set up the game engine:

what's the best version of resident evil 3:nemesis? : r/residentevil

It looks like you're looking for a way to download (the reverse-engineered GTA III source code) specifically from SourceNext (a Japanese digital distributor) or perhaps the SourceNext version of GTA III to use with re3.

If you already own the GOG or original retail PC versions, you can use the Unofficial SourceNext 1.1.0 Conversion Patch available on Nexus Mods to convert your game files into the SourceNext format. Essential Setup & Modern Improvements

: It features uncompressed cinematic videos at 60 FPS, the highest quality available in any release.

While modern remakes are popular, the Sourcenext version remains the peak "classic" experience for several reasons: