[tex-eplain] footnotes

[Karl Berry]

    I've never needed \global before, but it does fix the problem
    here. Maybe someone who understands eplain better than I can explain

It's not about Eplain.  \output is executed by (primitive) TeX in a
group.  But here we want the \footnotenumber assignment to persist after
\output is done.  Hence \global.

By the way, I suspect there are cases where the per-page footnotes would
end up numbered incorrectly with this method, like if a footnote gets
split across pages, or maybe read, considered and rejected for the page
break, and then put back on the main vertical list for more processing.
Insertions are complicated and asynchronous.  But if it works for your
document, then great :).

    >> Also has anyone got a hack they would like to share of how to put
    >> footnotes into two columns at the foot of the page?

Sounds like critical edition-level complications.  The "quick" hack
would be to rewrite the footnote handling from plain.tex's \pagecontents
to split the \footins box instead of simply \unvbox-ing it.  Probably
not too quick.  A real solution, I have no idea about.  I wonder if
edmac or some other (plain) package could be employed.

Good luck,
karl