LuaTeX seems to be the best for overall typesetting quality. You can get proper rendering of modern fonts.
IMO the underlying issue is that TeX can’t really be parsed by anything other than Tex because it’s too full of macros that change the language. I think a better language would generate a well-defined AST, and different tools could compete to render it well.
IMO the underlying issue is that TeX can’t really be parsed by anything other than Tex because it’s too full of macros that change the language. I think a better language would generate a well-defined AST, and different tools could compete to render it well.