All below package names are from the Arch repositories. Some packages are exclusive to the AUR only.
Windowmaker dockapps may require manual source code fixes.

Required packages

the bare minimum of this setup

xorg-server                 - I don't use Wayland and almost nothing on this list supports it.
windowmaker                 - The desktop. Self explanatory.
wmclock                     - The clock, you'd be a loser without one.
wmsystemtray                - Support for XDG tray icons, required for many applications.

Optional packages

part of xinitrc or basic utils

ly                          - Minimal ncurses session manager. Any replacement is suitable.
kitty                       - OpenGL 3.2 terminal emulator. Any replacement is suitable.
picom                       - Compositor for drop shadows and hardware-accelerated rendering.
kmix                        - KDE's Qt frontend for ALSA. Any replacement is suitable.
xscreensaver                - Screensaver pack for X server by Jamie Zawinski.
ckb-next                    - Free software reimplementation of Corsair iCUE for select keyboards.
protonmail-bridge           - Local IMAP server for encrypted Proton accounts.