3 ms·It is.by bazoom42 1y agoIt is.immibis 1y agoXHTML 1.0 was, and they evolved it incompatibly.bazoom42 1y agoThere was an ill-advised XHtml 2.0 project which was supposed to be incompatible, but it was abandoned. Currently xhtml is defined as an alternative “serialization” of html, but the semantics are exactly the same as html.