This site is created using a static site generator called hugo. There are many others, few example are Jekyll or Hexo. For the book I’m writing (read) I use a different tool called Sphinx and helps organizing the content you want to publish.

How most of these site builder applications work is the following: You start by choosing a tempate to use, or code your own; load your images and other static files, and write each of your website’s pages to shape it the way you want it to be.