"We have also benefited from the various open-source packages on which this textbook depends (see appendix G). The typesetting of the code was done with the help of pythontex, which is maintained by Geoffrey Poore. The typeface used for the algorithms is JuliaMono (github.com/cormullion/juliamono). The plotting was handled by pgfplots, which is maintained by Christian Feuersänger"

?

Here's the github repo used to create books in the same style: https://github.com/sisl/tufte_algorithms_book

Note that this repo is from the same author as the book.

I recognize the LaTeX theme, it's the Tufte-style book theme: https://www.overleaf.com/gallery/tagged/tufte

Everything else is probably just LaTeX magic