This site is implemented as a static web site. The tools available today allow these sites to be rich in content, and yet lightweight in infrastructure – and hence very inexpensive and still easy to maintain.
Hugo is one of the more popular static site generator technologies, it was selected for this site because of its broad support and small footprint – a pair of features that together make a compelling argument.
Github is possibly the most ubiquitous source safe system, the service is easy to use with git and being so ubiquitous is hard to argue with.
Netlify is the newer part of this stack; these folks really are a Content Delivery Network, but what makes them exciting to me is how they have turned Docker containers and a neat bit of IT savvy into an easy-to-use automatic site deployment process – just check the bits back into Github and within a minute or so the new content is pushed out to the production servers. Simple and smooth.
A lot of static web sites look relatively similar, and that is fine – content, not chrome. Many static sites are blogs running some 'skin' that changes the colors and perhaps the typeface, but their layout is still mostly full of one-page articles that are comprised of one long column. This site had some different goals, and some different tools were used to achieve those goals.
This site is based on the B-side theme for Hugo. This theme, inspired by the writings of Edward Tufte and several related projects, seeks to create a straightforward web-centric implementation of much of what makes these books and materials beautiful and very readable.
The other reason why many static-site based blogs look similar is because the common markup is very simplistic and not designed to be capable of a lot of variations.
This site, and the B-side theme, takes advantage of Hugo's support for reStructuredText. While still a plaintext markup, reStructuredText is a more mature and robust solution designed to be able to handle complex documentation publication needs. For a sample of the features of this theme, see the Tufte example.