The xhtml page is designed with a single layout and without any external dependency. That is the css, java-script, svg are all embedded. This layout makes it possible to save the file for offline use and is also easy to search with the navigator. Furthermore the css print properties will create a nice pdf and a printable booklet to keep at hand.
This approach with examples has of course its weakness as one can't include everything and some operating systems or different kernel version will not behave in the same way. I try to keep the document as "small" and compact as possible. Also calling this a "Unix" toolbox is not accurate as it covers mostly Linux and FreeBSD. However I will add more Solaris and OS X commands in the future. Take a look at the Rosetta Stone for Unix for a good complement.