fhDOOM is described as 'Modernized DOOM3/idTech4 engine: ported to modern OpenGL (core profile), enhanced visual effects, improved performance, improved editor, more to come' and is an app. There are four alternatives to fhDOOM for a variety of platforms, including Mac, Windows, Linux, Self-Hosted and Microsoft Edge apps. The best fhDOOM alternative is dhewm3, which is both free and Open Source. Other great apps like fhDOOM are RBDOOM-3-BFG, UQE Doom 3 and D3wasm.
dhewm 3 is a Doom 3 GPL source port, known to work on at least Windows, Linux, macOS and FreeBSD.
dhewm3 is the most popular Windows, Mac & Linux alternative to fhDOOM.
dhewm3 is the most popular Open Source & free alternative to fhDOOM.
RBDOOM-3-BFG is based on DOOM-3-BFG and the goal of this port is to bring DOOM-3-BFG up to the latest technology in 2021 making it closer to Doom 2016 while still remaining a DOOM 3 port regarding the gameplay.
UQE Doom 3 is a source port for Doom 3 that primarily focuses on quality of life improvements such as wide-screen support.
D3wasm is an experiment to port the id Tech 4 engine (aka. “Doom 3 Engine”) to Emscripten / WebAssembly and WebGL, allowing to run games such as Doom 3 inside modern Web Browsers.
D3wasm is the most popular Self-Hosted alternative to fhDOOM.
