With that and the author's mention of using PHP for a custom blogging setup, I'm guessing it's being dynamically generated by PHP still.
I've toyed with having a minimal blog, where I simply drop text files with file names beginning with their date in a folder and rely on directory indexes as a "home page".
For instance, you want to sort by publish date, which isn't the same as file creation date. If you add it to the file name, to sort by that, then you can no longer use file names for urls, at least without some transformation.
So I was really curious how others were dealing with that in a clean way.