[gsnedders]

Pretty much no, because it'd be practically useless. And I don't think anyone has the willingness to spend time or money on something that will essentially just be a toy.

There's been plenty of work on moving the standards so that there are actually implementations of them, instead of them being practically useless at best and misleading at worst (given doing input validation based on a spec that nobody actually implements is just outright dangerous), with HTML 5 and much of CSS 2.1 leading that charge (though CSS 2.1 still has massive blackholes, notably table layout remains largely undefined, though that is finally being worked on).