Source port

A source port, a portmanteau of source (code) and port(ing), is a software project based on the source code of a game engine that allows the game to be played on operating systems or computing platforms with which the game was not originally compatible.

Source ports are often created by fans after the original developer hands over the maintenance support for a game by releasing its source code to the public (see List of commercial video games with later released source code). The term was coined after the release of the source code to Doom. Due to copyright issues concerning the sound library used by original DOS version, id Software released only the source code to the Linux version of the game. Since the majority of Doom players were DOS users the first step for a fan project was to port the Linux source code to DOS. A legitimate source port includes only the engine portion of the game and require that the data files of the game in question already be present on users' systems. Source ports are in no way meant to encourage copyright infringement of software.

Source ports share the similarity with unofficial patches that both don't change the original gameplay as such projects are by definition mods. However many source ports add support for gameplay mods, which is usually optional (e.g. DarkPlaces consists of a source port engine and a gameplay mod that are even distributed separately). While the primary goal of any source port is compatibility with newer hardware, many projects support other enhancements. Common examples of additions include support for higher video resolutions and different aspect ratios, hardware accelerated renderers (OpenGL and/or Direct3D), enhanced input support (including the ability to map controls onto additional input devices), 3D character models (in case of 2.5D games), higher resolution textures, support to replace MIDI with digital audio (MP3, Ogg Vorbis, etc.), and enhanced multiplayer support using the Internet.

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