I don't know the exact year that file format was made, but you had to think about performance more than wasting so much memory and cpu cycles to have a fancy fi

I don't know the exact year that file format was made, but you had to think about performance more than wasting so much memory and cpu cycles to have a fancy file format, no? Ofcourse that era Microsoft tools didn't think much about interoperability outside of Microsoft ecosystem. But to me it seems that them having some XML based file format at that time would be silly and have disadvantages. XML actually was started on '96 and published on '98 https://en.wikipedia.org/wiki/XML https://en.wikipedia.org/wiki/XML .doc seems to be used starting from '89 > The format used in earlier, pre-97 ("1.0" 1989 through "7.0" 1995) versions of Word are less known https://en.wikipedia.org/wiki/Doc_(computing) https://en.wikipedia.org/wiki/Doc_(computing)