After you have created a GNUstepWeb application, you might want to deploy it. The Apache 2 adaptor is a module that loads into your apache server. If somebody asks your web server for a dynamic web page it will forward the request to the appropriate application instance.
The main difference between the older adaptors and the new one for Apache2 is that all configuration is done per virtual host context. In addition, no special config file is nessesary. All can go into httpd.conf.
ShowApps on will dump a list of configured applications.
ShowApps off hides that list.
App Name=appname Instance=instancenumber Host=IP or Hostname:port
ShowApps on App Name=TCWebMail Instance=1 Host=10.1.0.1:9901 App Name=PBX Instance=1 Host=127.0.0.1:9001
If the adaptor receives an request it cannot forward to the requested application, it will list the configured applications if ShowApps on was configured. Otherwise just a useless page is displayed.