LWN: The Windowing patent

Software patents strike again, and this time Linux could be
directly affected.

“It seems that McDonnell Douglas has been awarded a patent on a
technique called “windowing” which is used for dealing with year
2000 problems. The essence of this highly advanced and obscure
algorithm, which converts two-digit years to four digits…”

“This patent will almost certainly be overturned by
demonstration of prior art; see, for example, time.c from kernel
1.2.13, courtesy of the Linux Cross Reference site. The Linux
kernel was using windowing in early 1995, if not before. One of the
beautiful things about free software is that it makes finding (and
documenting) prior art a relatively easy thing to do….”