HTML does not include the Web. It is a markup language. Period. The content
of the Web pages a user visits is not Trisquel's business. Trisquel aims to
provide an operating system where the user would never accidentally run or be
invited to run proprietary software. That means, in particular, that the user
enjoys freedom 0: "the freedom to run the program, for any purpose". When the
program is a Web browser, the user must therefore be free to read whatever
she wishes to. Including proprietary manuals. In the same way, Trisquel
should not (and does not) implement technologies that aim at preventing the
user from running proprietary software. Those would be DRMs! And no, that is
not in contradiction "with providing an operating system where the user would
never accidentally run or be invited to run proprietary software".
JavaScript scripts are not content. They are programs that are executed on
the computer of the user (not on the Web server). When such a script is
obfuscated, it is proprietary software. Indeed, among the four freedoms
defining a free software, the freedoms 1 and 3 require an access to the
source code and having an access to an obfuscated code is, for the practical
matter of exercising freedoms 1 and 3, the same as not having access to the
source code.
Unlike the BIOS/EFI, it definitely is possible to use, today, a computer (and
the Web) without executing obfuscated JavaScript. Like all proprietary
software, Trisquel should prevent the user from accidentally running it (but
not technically prevent her to do so).
LibreJS looks like the right solution. Unfortunately, it is far from perfect
and frequently goes in the way of reading Web pages with non-obfuscated
JavaScript (which is not problematic). I am not not sure whether that
significant issue makes LibreJS worse than the problem it solves. Indeed,
LibreJS could discourage many users who want an operating system that is not
only free but also usable.