Is CSS3 part of HTML5?
It means if a browser supports CSS3, will it support HTML5 elements too?
I had tried HTML5 elements in IE9, They didnt work.
But CSS3 properties( like box-shadow, border-radius) do work in IE9 fine by doing little changes in html file (By putting this tag <!DOCUMENT HTML>).
So what do we have to say now?
Does IE9 supports HTML5 or It supports only CSS3 but not HTML5?
HTML5 and CSS3 are completely separate things, so browser support for one does not always mean the other, especially considering that HTML5 is still a working draft (CSS3 is currently a recommendation).
That being said, with todays modern browsers, most will support the common HTML5 and CSS3 features. Internet Explorer 9 still requires a little help in regards to HTML5, you can use what is known as a HTML Shiv (or shim) to ‘polyfill’ support. Here is a guide to what IE9 supports: http://www.impressivewebs.com/html5-support-ie9/