This installer will create the following in your "Wolfenstein ET" folder:

etpub
  folder that is used to store etpub-specific configuration files (.cfg) and custom ET packages (.pk3).
etpub.app
  a copy of 'Wolfenstein ET.app' with etpub installed into it.
etpub_server.command
  a script that starts 'rtcw_et_server' telling it to:
  1. Use 'etpub.app' instead of 'Wolfenstein ET.app'
  2. Use fs_game 'etpub' instead of 'etmain'
  3. exec server.cfg

To remove etpub from your system, simply move these 3 things to the trash.

This installer will also copy example .cfg files to the etpub directory if they do not exist already. These files are heavily commented to aid in configuration. You can edit them with a text editor such as TextEdit.