Remember,
Xenix was originally a Microsoft product, they then sold it off
to SCO (for a % ownership in SCO)
Actually Xenix was never a Microsoft branded product. It was Microsoft's
but they only sold Xenix as OEM'd versions to vendors like SCO and lots
of HW vendors who then added they modifications to support their specific
products (like Apricot, whose machines were far from plain PCs).
We may not all mean the same thing by "branded", but ISTR
seeing the banner "Microsoft XENIX" on that Radio Shack 68000
machine whose model number I can never recall...
-dq