any discussion of "what .epub supports" is dishonest dialog.
It is not dishonest dialog. But, The wrong discussion.
because the truth is that different .epub viewer-programs
"support" different subsets of the "official standard", and
This is the true crux of any argument. It is not the standard, but those
that try to implement it, and fail miserably !
thus the _reality_ of the format is that it's one huge mess,
But, the mess arrives from the fact that the standard does not state, you
have to implement said feature! At least the entire feature.
Here Unicode comes to mind.
And most reader producers do not take the time and money to implement
it fully or even partially so that it will support most western languages!
So even if I produce a ebook that follows the standard, I can not find a
reader that will display it! That, with using some tricks. These tricks make
for the nasty experience.
a "standard" that's been embraced and extended to death,
whenever it wasn't locked-down with d.r.m. to begin with.
and that is exactly how the corporate publishers _want_ it.
because they're trying to stave off the revolution that will
short-circuit their cash-registers and ruin their business.
so what are they doing with .epub? why, coming out with
_a_3.0_version_, of course, the better to boggle you with.
you think things were confusing and fragmented _before_?
well let's throw audio and video into the mix too, because
the last decade of the web _proved_ they cause infighting.
throw in some javascript, and html5, maybe flash as well,
in order to _ensure_ that e-books are a nasty experience.
it's no accident that amazon outpaced i.d.p.f. even while
using a format that was supposedly "inferior" to .epub…
Remember, your post about eco-system!
but the end-run is inevitable, so all i.d.p.f. can do is stall it.
study the "history" all you want, most especially if you want
to distract people from _the_future_. but if you want to go
_forward_, we need _a_clean_break_ from crap like .epub...