I meant if I had designed it from the start. Then everything is a tag, no attributes, no quotes, equal signs, etc.

How about JsonML; i.e. XHTML but in JSON format to make it less verbose / further improve integration with javascript?

JsonML is pretty efficient when auto-generated from HTML source. I use it as an intermediate form for client side templates ( http://duelengine.org ) but I don't write it by hand. Its regularity makes it a perfect candidate for output from a parser/compiler.

You'd want to kill yourself pretty quickly.

JSON is great as an interchange format, but there are many reasons editing it by hand is painful, lack of comments and lack of newlines in strings not being the least of them.

There's no syntactic difference between an attribute, an object and an array.

you can't nest tags into attributes