I started this project back in 2015, to translate the TeX original specification into an easily parsed format (s-doc), and to create an HTML rendering of that format as a proof of concept. I finally finished it this year.

The project is here: https://codeberg.org/dlowe/metaspectre/

Differences from the Hyperspec (from the README): - Most importantly, it is free to modify and distribute. - The original TeX is very hard to parse and use for things other than generating a printed copy. The Hyperspec is an HTML rendering which can be parsed as HTML, but loses a lot of information. The Metaspec has an easily parsed intermediate form that can be used for all kinds of purposes, like converting into lookups. - Math equations are rendered using MathML. - Includes the acknowledgements and appendix sections. - Uses progressively enhanced Javascript to provide search and light/dark theme switching. - Incorporates over 145 patches for content, using corrections accumulated over the years, and documented in the errata page. - Includes TeX comments, which can contain interesting historical data. - Includes links and identifiers to bibliographical references.