"js" in "pdf.js" stands for JavaScript. But it is a script that comes with
the Web browser and that is free software.
Of course you can download the PDF. Even when displaying a PDF through the
Web browser, you actually downloaded it. The PDFs are under distributed the
Creative Commons Attribution-ShareAlike 4.0 International License, as the
last slides indicates. To easily modify the slides one needs the LaTeX
Beamer. Links to both the PDFs and the source are given on that page page:
http://dcc.ufmg.br/~lcerf/en/mda.html#slides
I would like to point that those slides have little to do with Shell
scripting and everything to do with specific commands: the GNU text
processing commands. Of course, a script can use those commands. See
http://dcc.ufmg.br/~lcerf/en/utilities.html#pdf-page-grep for a tiny script
that mainly relies on 'grep' and
http://dcc.ufmg.br/~lcerf/en/utilities.html#trivialibre for another tiny
script that uses 'sed'. Both scripts are heavily commented for learning
purpose (I am a professor if that was not clear) and Lucas Westermann made me
the honor to write two pedagogical articles about them (links given on the
page).
