See the code in this HTML file about downloading the triples for this demo. Then, if you are running a Gruff server as shown below in web browser mode (-b yes), without starting a local client in a web browser (-l no), without exiting the server when a client exits (-x no), connecting to the Gruff server at port 9009 and allowing clients to run on ports 9009 through 9013 (-o 9009-9013), telling Gruff to start up its HTTP server at startup time and to share the same port (-t 0), allowing Gruff to serve five clients at a time (-m 5), acting as a launcher to run an instance of Gruff for each client (up to a limit) that requests one (--launcher yes), writing a log file at log.txt in the Gruff folder (-g log.txt), and publishing demo this file, then pressing the Run Gruff Below button will tell the (invisible) iframe element to to display Gruff in this web page.
gruff -b yes -l no -x no -o 9009-9013 -t 0 -m 5 --launcher yes -g log.txt --file-to-publish http-interface-demo.html
Other notes: Adding --disable-menus to the command line (with no argument after it) would remove the Gruff menu bar and disable other interaction, to control Gruff programmatically only. And adding --custom-title with a string argument would replace the usual text in the title bar with arbitrary text. Using -x no keeps the Gruff server running while various users connect and disconnect, though it also means that you will need to use some operating system facility to kill the Gruff server eventually.