That depends on your specific goals. But essentially, XML schemas are sort of like attribute grammars, except with an unnecessarily convoluted syntax, and yet more limited in their expressiveness than attribute grammars (because whatever constraints you need have to be procrusteanized into XML schemas).
Even if you were to stick with XML semantics as is, you could improve the syntax to be actually readable and eliminate the angle bracket tax [1, 2].
Alternatively Carl Sassenrath was pushing Rebol in the past. See his blog post "Was XML Flawed from the Start?" - http://www.rebol.com/article/0108.html
Even if you were to stick with XML semantics as is, you could improve the syntax to be actually readable and eliminate the angle bracket tax [1, 2].
[1] http://blog.codinghorror.com/xml-the-angle-bracket-tax/
[2] http://blog.codinghorror.com/revisiting-the-xml-angle-bracke...