Comment HTML5 is still a draft (Score 1) 170
HTML5 is still a W3C Working Draft standard (see http://dev.w3.org/html5/spec/) and is still changing so browser developers are slow to spend effort implementing it. Even after it becomes an official 1.0 standard, some browsers may not implement parts of it for years, so some amount of browser-specific code (and occasional non-availability of some features on some platforms) will always be a fact of life when building Web UIs.