Bill Gates purchased CPM-86 from Seattle Software for $50K ... and
    this became the original MS-DOS 1.0.  CPM-86 was just a port of
    Gary Kildahl's CP/M 2.2 from the 8080 to the 8086.

Um.  No.  At the time of MSDOS 1.0, you could purchase CPM/86 as a competing
operating system for the PC (remember competing operating systems?  There
used to be competing operating systems...)  The original MSDOS was more like
CPM 2.2 than CPM86 was - I think the CPM people decided they wanted to
"advance" while the msdos people just copied.  I don't know if microsoft
subsequently purchased CPM/86 or not (sounds like "first meat" for the
anti-trust case if so.)  Rumor has it that msdos was chosen over cpm86 for
IBM's personal computer because the cpm people were "too busy" to talk to
some IBM representitives without an appointment.  (um, wasn't CPM from
"digital research" or somesuch, not Seattle software?  Maybe there were
several "CPM86" variants.)  Note that at the time, microsoft was already
a major supplier of BASIC implementations for several architectures.

I'd describe Windows before W95 as an attempt to implement a window-based
operating system that was NOT like apple's windows.  Unfortunately for
microsoft, apple's windows were already based on a LOT of xerox parc
research, and comparitively early windows was just a hack.

Xwindows and sunOS and related I'm not as much acquainted with the
development history of.  In a sense, they seem to me to be very different in
that their primary purpose is to implement JUST windowing, while apple and
uSoft windows serve as the primary user interface for everything.  At least,
I use X-windows every day, and mostly I start up a bunch of unix shells, in
which commands I issue sometimes open additional windows.

BillW