I agree with the spirit of this comment: good typesetting is a delight, and TeX is the best tool I've seen for achieving it. We are lucky that its author made the result of his researches freely available, and that a community has kept it alive. I'll just point out that simply using LaTeX does not automatically guarantee great typesetting (you have to know what you want) though it does provide a baseline of decent paragraphs at least. Nit: TeX/LaTeX do not inherently avoid rivers (though see https://tex.stackexchange.com/q/29049/48 and https://tex.stackexchange.com/q/4507/48), and the body font in this PDF is not Garamond but Linux Libertine.

The typesetting of this book seems due to Andres Raba (sarabander on GitHub), and the LaTeX is generated by a script from texinfo format: https://github.com/sarabander/sicp-pdf/tree/5b3a5b2/src