[tex-hyphen] pattern stability (was: gswiss in language.dat)

[Karl Berry]

    more and more difficult to talk about 100% backward compatibility
    unless one sticks with the same old distribution.

100% agreed :).

Nothing is perfectly stable, except Knuth's files -- but that's Knuth's
decision, and does not apply to anything else.  For that matter, even
Knuth's files have changed.  It is possible to construct TeX files that
work with version x of plain TeX and fail with version x+1.

100% backward compatibility has to be achieved by archiving the
software, as well as the TeX sources.  This has always been the case.

Now, because our whole community is very concerned about compatibility
in general, 99% compatibility, or 95%, or whatever, is generally
happens.  For instance, I have sucessfully run TUGboat sources from 20
years ago against a current pdfTeX and current TUB packages even though
all kinds of things have changed in the meantime.

Anyway ... Stephan, what's your point/concern?

k