Addendum the second (2/28/2018): Seriously, don't even bother reading the rest of this post. Use ECWolf. Forget about Wolf4SDL. Wolf4SDL is dead. I'm not even going to allow any further comments or questions about it on this post.
If you've stumbled across this post, you're probably looking for help with the same problem I once had: You want to play your copy of Wolfenstein 3-D and/or Spear of Destiny using the source port Wolf4SDL instead of the somewhat unreliable emulation of DOSBox, but you've found that the Wolf4SDL developer's website seems to be down and the documentation telling you how to actually get your game running seems to be nonexistent.
I'm here to help.
I'm going to talk about how to run Wolf4SDL under Linux first, because that's probably the version most people have had trouble with. If you're using Windows, just scroll down this post until you see "FOR WINDOWS USERS" in bold capital letters.
FOR LINUX USERS:
The game files need to be in the directory /usr/share/games/wolf3d and the filenames need to be written in all lowercase characters.
Some people won't need to read any more than the above sentence to grasp the solution to all their problems, but if you need me to start from the ground up, just keep reading.
I'm using Ubuntu to explain the process here because I haven't tried it with any other distributions; your distribution may require different commands to accomplish some of these steps.
I'm going to assume here that you've already installed Wolf4SDL via Ubuntu Software Center or Synaptic. That's the easy part. Now find your Wolfenstein 3-D game files and copy all the files with the extension .WL6 to their own directory on your hard drive. Copy only the .WL6 files; none of the others are needed. If you see a different extension, like .WL4 or .WL1, you have an early version; this shouldn't cause a problem but it will require a different command to run later. For the purposes of this post, I'm assuming the .WL6 files are in a directory named wolf3d inside your home directory.
For Spear of Destiny, the relevant file extensions for the above step are .SOD, .SD1, .SD2, and .SD3. Yes, you actually need to copy all of those.
Now you need to ensure all your Wolfenstein 3-D game files are in lower case. For some reason, Wolf4SDL requires the filenames to be all lower case, even though they're upper case as installed with every version of Wolfenstein 3-D I can think of. Look in the wolf3d directory in your file manager, and manually rename each .WL6 file with lower case characters (AUDIOHED.WL6 will become audiohed.wl6, and so on).
For Spear of Destiny, do this with all .SOD, .SD1, .SD2, and .SD3 files.
Now back up your newly-lowercased files somewhere so you won't ever have to do this step again.
Wolf4SDL will look for the Wolfenstein 3-D game files under the directory
As far as I can tell, Wolf4SDL cannot be directed to look for the files anywhere else. If there's a command to do this, it's been lost along with all the rest of the documentation.
Thus, open a terminal and type the command
sudo mkdir /usr/share/games
sudo mkdir /usr/share/games/wolf3d
Having created this directory, all that remains is to copy your game files into it:
sudo cp wolf3d/* /usr/share/games/wolf3d/
Now just type wolf4sdl-wl6 and press Enter; you should be up and running.
If you're using a different version in which the game file extension is not .wl6, consult the man page to determine which command to run by typing man wolf4sdl (this is the only thing the man page is useful for). You'll probably need to run either wolf4sdl-wl1 or wolf4sdl-wl4.
For Spear of Destiny, you will need to run wolf4sdl-sod and specify which mission to start at the command line thusly:
wolf4sdl-sod --mission 1
for mission 1,
wolf4sdl-sod --mission 2
for mission 2, and
wolf4sdl-sod --mission 3
for mission 3, obviously enough.
I don't believe this vital command line argument is mentioned in the man page. Bad developer, no biscuit.
FOR WINDOWS USERS:
Download Wolf4SDL and, if you want to play Spear of Destiny, make sure you also get Spear4SDL (may also be called Sod4SDL).
Unzip the files Wolf4SDL.exe, SDL.dll, and SDL_mixer.dll to the same folder as the game files with the extension .WL6. In my case, this folder is C:\Games\wolf3d\base.
For Spear of Destiny, put Sod4SDL.exe, SDL.dll, and SDL_mixer.dll in the same folder as your .SOD, .SD1, .SD2, and .SD3 files. In my case, this folder is C:\Games\sod\base.
For Wolfenstein 3-D, just run Wolf4SDL.exe and you should be up and playing.
For Spear of Destiny, you're going to need to add a couple of command line arguments. The quick way to do this is to create a shortcut to Sod4SDL.exe, right-click the shortcut and select Properties, and inside the Target: field add
--goodtimes. Your Target: field should then read something like
C:\Games\sod\base\Sod4SDL.exe --mission 1 --goodtimes
Click the OK button to save changes, and repeat for missions 2 and 3.
Now you can play Sod4SDL using one of your created shortcuts.
Another way to add command line arguments is to create a new text document, type in the text
C:\Games\sod\base\Sod4SDL.exe --mission 1 --goodtimes
then save the text document, giving it a nice descriptive name like sod4sdlmission1.txt.
Now rename the text file you just created to change the .txt extension to .cmd, thus sod4sdlmission1.txt will become sod4sdlmission1.cmd. You'll get a warning message saying "If you change a file name extension, the file may become unusable. Are you sure you want to change it?" click Yes.
Now you can run Sod4SDL by double-clicking the .cmd file.
I hope this post will be useful to someone out there who's had trouble figuring out how to get Wolf4SDL to start. If it has been, feel free to leave a comment to thank me. Or don't; that's fine. Either way, you're welcome.