> PDF forms now support JavaScript embedded in PDF files. Some PDF forms use JavaScript for validation and other interactive features.

The amount of complexity that one can put into a PDF is both surprising and a tad frightening.

I have an idea. Why not allow embedding a full browser engine inside of a PDF, complete with tabs and extensions? I hate having to leave Adobe Acrobat in order to read my Gmail, so I think this feature could be really useful. Anyone who builds a PDF can include their own custom browser that their users will love.

Well if you can run interactive javascript then you're mostly there, PDF is pretty much Turing complete so you can just crosscompile a browser into it using javascript to take care of the interactive parts, though you might need to rewrite the rendering logic.

PDFs are definitely not Turing complete. [0]

[0] https://www.cs.odu.edu/~zeil/cs390/latest/Public/turing-comp...

Depends on your PDF viewer... https://github.com/osnr/horrifying-pdf-experiments