A possibility may be to use the texinfo format (.texi) also for Winboard.
Makeinfo can make HTML output from .texi files, and that can be read by
everyone.
Well, the newer Windows help standard is based on HTML (which is then
compiled into a .chm file). I don't know very well how this works either, a
there was an automatic conversion utility for old-format to new-format help
projects, which gave me a lot of html files and some contents / index
files. Problem was that all colorization got lost, so someone volunteered
to edit the html to bring it back. But editing the html for adding new
descriptions won't automatically update the index and contents files, and
updating those by hand is a real pain.
By now I think the colorization is not very relevant anymore, however.
I think you can have conditional sections, so you can use the same source
for the xboard and winboard manuals. And as it is pure text, you can
automatically extract information about e.g. options from the C source and
insert it into the manuals. That would reduce much of the double work, but
it of course takes some work to set up initially.
I think this would be a very worthwile investment, especially since by now
XBoard and WinBoard have converged very much. Arun has proposed something
like this some time ago, and would look into it further, but unfortunately
he has been so busy for the past year that there has been no progress there.
