SIMIODE text in PTX format

[kcri...@gmail.com]

Not sure if this is the right group, but I couldn't find any other references on a PreTeXt list, so ... just FYI apparently the SIMIODE folks have converted their differential equations text to PTX:

https://qubeshub.org/community/groups/simiodetext/books/sample/frontmatter.html

It's behind an interesting paywall where you buy the pdf and then get the book free - I think?  Advertised as an "exciting and enriched Second Edition HTML version with interactive SAGE code".  Which sounds a lot like The Differential Equations Project too :-) but perhaps not quite as free.