DOS's use of
backslash as the path
delimiter stems from some ancient decisions made in the day of
DOS 2.0.
DOS 1.0 didn't
support directories, and thus had no need for a
path delimiter. When
directory support was added in version 2.0, forward
slash had already been assigned to be the
parameter delimiter, leaving backslash as the next best choice.
Consequently,
Windows adopted this scheme from DOS.