After my guide to install “iortcw” client for the 2001 released game Return to Castle Wolfenstein, I like to highlight also the “rtcwcoop” project which allows you to play through the missions with your friend(s).
You can grap the client from the project website: https://github.com/rtcwcoop/rtcwcoop/releases
Follow the guide for iortcw for the installation, it is pretty much the same procedure copying the original game date files over.
Have fun.
