Quake was the only game to support DOS and Win95 with TCP/IP multiplayer in one executable—deep dive explains how id Software did it

The article delves into how id Software managed to make Quake the only game to support DOS and Win95 with TCP/IP multiplayer in a single executable. Unlike other games of the era that required separate executables for different operating systems, Quake used nearly the same codebase for both. To achieve this, id Software integrated DPMI extenders and collaborated with the djgpp toolkit to ensure cross-platform compatibility. The game also incorporated Mplayer's match-making software for in-game browsing and Windows 95's Winsock TCP/IP layer interaction. By including genvxd.dll, Quake seamlessly ran on both DOS and Windows without the need for separate installations. For a more in-depth technical analysis, readers are directed to Fabien Sanglard's detailed breakdown.