I’ve verified that these steps work (for me anyway, YMMV). I’ll probably look at improving it slightly (and definitely cleaning up the UI of the “showdown.php” script), but for now it’s functional. You should be able to follow these steps to get set up with the entire system.

  1. Check out the project to a directory on your machine/server
    svn co http://svn.url.com/wpshowdown showdown
  2. Set up a local hostname to point to that directory (makes life a lot easier, and the only way I’ve tested this at all). I’ve been using “http://showdown/” so if you use that then it’ll make configuration a little easier.
    1. Configure Apache with a VirtualHost (and then restart Apache). This is mine:
      # WP Showdown
      <VirtualHost 127.0.0.1:80>
        ServerName showdown
        DocumentRoot "/private/var/www/dev/showdown"
        DirectoryIndex index.php
      
        <Directory "/private/var/www/dev/showdown">
         AllowOverride All
        </Directory>
      </VirtualHost>
    2. Change your /etc/hosts (or similar) file to resolve that hostname to your machine. Here’s what it looks like:
      # WP ShowDown
      127.0.0.1       showdown
  3. Create a clean database, called whatever you want — make sure you use collation and set it to “utf8_general_ci”
    CREATE  DATABASE  `showdown`  DEFAULT  CHARACTER  SET utf8 COLLATE utf8_general_ci;
  4. Hit http://showdown/ to start the WPMU install process — DO NOT LOG IN AT THE END OF THE INSTALL.
    1. Use the Sub-directories option!
    2. Set your DB options
    3. Enter a name/email
  5. Open a new window and manually hit http://showdown/showdown.php to continue with the custom installer. You’ll need the password from the WPMU installer, thus the new window.
  6. The last step of the custom installer will tell you to log in again. Once you log in everything should be ready to go.
  7. Your admin panels are:
    1. WPMU: http://showdown/wp-admin/
    2. bbPress: http://showdown/forums/bb-admin/ (although you shouldn’t need to go here for much, because it’s linked from WPMU)