The name Doom engine refers to the parts of the software that
power or run the Doom and Doom II games, as opposed to the
assets and resources (data) of said games. In a strict sense,
the engine is the executable elements of the games, based on the
corresponding source code, as opposed to WAD and lump files.
Various versions of the engine were released by id Software for
the PC games, one per release but often shared by both games, as
the same executables are used for both, only renamed
accordingly. The engine is composed of a rendering engine which
structures game levels and handles movement, effects, and
obstructions during play, and an auxiliary Doom networking
component to connect computers during multiplayer games.
Additionally, the engine includes a sound management system, of
which, unlike the rendering and networking functionality, the
sources were not fully released to the public, as they included
proprietary code written by Paul Radek. The latest version of
the engine released for the games is the on