DoomXS

DoomXS, short for Doom eXtra Small is a source port developed by Jim Valavanis (Jval) developed from a very early version of Jval's other port, DelphiDoom. DoomXS serves as a minimalistic port in nature, in which it intends to fill in the absence of a minimal source port of Doom developed in the Pascal programming language and which has low system requirements. It can run on and 128 MB of RAM.

It includes a launcher, called LaunchXS.

History
DoomXS is based on a very early version of DelphiDoom, namely version 0.1 released on October 15, 2005. It was in development since early 2021 with the first release being version 1.0.2.133, released on September 30, 2021. Development was discussed in a Doomworld thread titled: "DoomXS - eXtra Small source port." .

Features
limit                        : old    * k   = new --- visplanes[MAXVISPLANES]      : 128    * 2   = 256 SAVEGAMESIZE                 : 180224 * 5.1 = 942080 vissprites[MAXVISSPRITE]     : 128    * 2   = 256 linespeciallist[MAXLINEANIMS] : 64    * 256 = 16384 openings[MAXOPENINGS]        : SCREENWIDTH * SCREENHEIGHT
 * 640x400 display (8 bit color)
 * Raised static limits:
 * Other limits, such as, and  remained unchanged
 * relies on a implementation seen in a Doomworld thread titled: "Reasonable static limit for MAXOPENINGS? "
 * Support for and  environment variables
 * Low hardware requirements
 * No zone memory allocation at startup. This allows DoomXS to launch instantly
 * Launcher application called LaunchXS
 * Small codebase, making it an ideal starting point for Pascal programmers