[YeGoblynQueenne]

>> Unicode maintains the position that plain text is unsuitable for this sort of thing and markup languages are preferred.

Well, I think that's an unreasonable position. The most intuitive way to enter mathematical text with a keyboard is to enter the symbols you want to enter, directly, as characters. I mean, nobody asks me, as a Greek speaker, to enter (hypothetical markup) \{greek_letter_xi} for χ or \{greek_letter_ypsilon} for υ, etc, thank the gods. Why do I have to use markup for the simplest things, like fractions and exponentials?

All symbols for math may be in Unicode, but there is no font supporting all of them. It's not Unicode that's at fault here, of course.