>>15477251
1. Download the quakespasm-0.93.1_*.tar.gz, where in place of * will either be linux or amd64 depending on your processor: 32-bit or 64-bit respectively.
2. Extract the archive either with some GUI program or through terminal with tar -xf <path to archive>.
3. Inside the extracted directory will be three files: quakespasm, quakespasm-sdl2 and quakespasm.pak. First two are executable, the actual engine. If they are not – make them, either via your file manager or through terminal with chmod +x <path to quakespasm[-sdl2]>. The last one contains some assets used by the engine, stuff like menu background. If you're going to use engine with the -fitz flag, which disables some of the visual changes, you can delete quakespasm.pak.
4. The engine requires certain packages to function. First, you're going to need either libsdl or libsdl2, depending on which executable you're going to use. The pros and cons of each are not so obvious, so it's better to just try out for yourself and see which one works best. Second, you'll need libraries for music playback: libvorbis0a, libogg0, libvorbisfile3, libmad0. If for some reason I got their names wrong use the package manager to search for correct names, in case of terminal it'll be apt-cache search <keyword>.
5. You install all these packages either by typing sudo apt-get install <package names> or via some GUI package manager (I don't have experience with any).
6. The engine is ready to go. All you need now is the game files: folders id1 for Quake, hipnotic for Mission Pack 1: Scourge of Armagon and rogue for Mission Pack 2: Dissolution of Eternity. Place these folders in the same directory as the executable. Inside these folders the only files you need are *.pak files, delete everything else.
7. For music to work you have to create folder music inside the game directories and put the music files there. QuakeSpasm supports OGG Vorbis and WAVE, not sure about other formats.
In the end your directory should look something like this:
Quake/
id1/
music/
…
pak0.pak
pak1.pak
hipnotic/
music/
…
pac0.pak
rogue/
music/
…
pak0.pak
quakespasm
quakespasm-sdl
quakespasm.pak
After that you can just launch the engine and play the game. For more info on the console commands and how to install mods just read the web.