For QuakeC addons:
Most QuakeC addons fall within the following three categories. Just find the scenario that most fits the patch you want to install and follow the directions.

• If the file you downloaded contains a file called PROGS.DAT, copy it to a subfolder in the Quake folder and, at the command prompt, run it like this (replacing FOLDERNAME with the name of the folder containing the file): QUAKE -GAME FOLDERNAME
• If the file you downloaded contains files with the extension .QC but does not contain a file named PROGS.DAT, you need to download QCC and follow these directions:
  1. Create a folder named QCC parallel with id1, and extract QCC.TAR.GZ to it.
  2. Copy QCCDOS.EXE and CWSDPMI.EXE to a folder in your path (for example, C:\)
  3. Create another folder parallel with id1 and copy the V101QC folder from the QCC folder into that.
  4. Copy the *.QC files and (if applicable) the PROGS.SRC file from the .ZIP file that contains the QuakeC patch you want to install to the V101QC folder inside the folder you made in step 3.
  5. Run QCCDOS from the V101QC folder mentioned in step 4. That will compile all of the files listed in progs.src and (if there aren't any errors) generate a new PROGS.DAT file in the parent directory (the folder you made in step 3).
  6. At the command prompt, go to the Quake folder and run Quake like this (replacing FOLDERNAME with the name of the folder containing the new PROGS.DAT): QUAKE -GAME FOLDERNAME
     
  (note: the above QC files are for Quake 1.01 but work fine with 1.06. If you want the 1.06 .qc files to work with, get them here
• If the file you downloaded contains only a .PAT file, follow the directions in this documentation file.

1. Create a folder in your ID1 folder called MAPS
2. Copy the .BSP file to the MAPS folder
3. Run Quake, go to the console (press ~), and type map filename, replacing filename with the name of the .BSP file minus the .BSP. Example: map tod

• These are used by level authors when making new levels
• The level editor needs these files so you can preview the textures and also for a few more reasons
• Unless you are a level author or want the textures for some reason, these will be of no use to you.