This is a theme for Hugo, a static site generator. The theme is based on the WordPress theme with the same name by Kit MacAllister.
I ported this theme from WordPress because it was the theme currently in use by my website. It does not have all the features the original theme had, I just ported the features I needed to get the site to look like the old version.
Check out this theme into the themes/ directory of your site and use it with hugo -t hugo-brunelleschi or specify it as default in your configuration file.
The site linked to by the original theme seems to have gone offline. The new page of Kit MacAllister seems to be kittrick.co.