I am playing with some ideas for writing a book on
Cross-Platform development in C.  I would appreciate
your comments on what things you have found to be
the most critical in writing a program that runs
on more than one platform (e.g. DOS, various UNIX
systems, Windows).

I would appreciate any responses, no matter how short.
I do have some ideas from my experience, but don't
want to bias you with them.

thanks

(REPLY by email only; thanks)