As it is written it will execute as a standalone, but you can modify this easily into an applet.
Have a look at the files in this directory. Invoke with a URL for reading. The URL should be an http URL on the server from where you just loaded this page. E.g.
http://www.ifcomputer.com/MINERVA/home.html
For a "file" URL you will get a Java Security Exception depending on the setting of your browser. For a non-existing URL you will get a "existence_exception" exception from MINERVA. For an invalid URL specification you will get a "domain_error" error from MINERVA.