[tex4ht] TeX4ht upgrading: doesn't work

[Karl Berry]

Hi Bill,

    I believe that there should be no issues with correct LaTeX2E

I talked to Frank and Will about this at the last meeting.  If a
document uses *only* core LaTeX features, then, yes, it could work in an
L3-only format.  Both I and they think the number of such real-world
documents is quite small.  I.e., that do not load, say, hyperref or url
or ltugboat or ...

I stand by my statement :).

    since Karl posted his comment I've yet to find an example
    that fails with expl3 loaded.  Am I missing something?

I was responding to the original query about (what I took to be) a
LaTeX3 format/program, not loading the LaTeX3 packages under LaTeX2e.
That is completely different, and indeed, the LaTeX developers deserve
much credit for making the LaTeX3 packages loadable under 2e and not
breaking compatibility to any significant degree.  To my mind, that is
the major reason why the L3 packages have met with a fair number of
users.

karl