Thanks.
Sorry about that. I grabbed the first link from Google which would always give the correct link, seems Google has changed the priority of the versions.
There are a few versions out there and that one is special in that it took the book and integrated it with SWISH, not all of the kinks were worked out of it.
The one that I find currently works best is the one with just the web pages and then using a separate running instance of SWI-Prolog. Try this link
https://www.let.rug.nl/bos/lpn//lpnpage.php?pageid=online
For much more info also see Useful Prolog references