I recall I had XHTML 1.x Strict served as XML working in Internet Explorer (that would have been my primary testing/dev browser at the time, even). It was certa

I recall I had XHTML 1.x Strict served as XML working in Internet Explorer (that would have been my primary testing/dev browser at the time, even). It was certainly no cakewalk, but it was briefly possible. As I recall it the XML mime types stopped working again shortly after HTML 5 became the headwind.