gpl-2.0.txt contains the official GPL v2.0 license from:
http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt

It applies to this software, namely the ygphpcgi.sh script. This script can be used in CGI mode in a web server, for use with PHP files.

Default configuration is to have PHP CLI installed in /opt/php5/bin/php, but this can be changed.
Defaurt configaration is to have PHP sessions stored in a php_sessions directory, next to the one containing the script itself.
Both these defaults can be changed by modifying the first two lines of the script.

Example configuration for Mathopd, for using this script:

Control {
  IndexNames { index.php index.html }
  Types {
    text/html { html htm }
    text/plain { txt }
    image/png { png }
    image/jpeg { jpg jpeg }
    text/css { css }
    text/javascript { js }
    application/octet-stream { * }
  }
  External {
    /path/to/ygphpcgi.sh { php php5 phtml }
  }
}

Server {
  Port 80
  Virtual {
    AnyHost
    Control {
      Alias "/"
      Location "/path/to/web/site/root"
    }
  }
}
