While most versions of IE (even older ones!) are supported well, IE9 has a little conflict to work around. To support IE9, you will need to wrap a video
element wrapper around the source elements in your picture
tag. You can do this using conditional comments, like so:
<picture>
<!--[if IE 9]><video style="display: none;"><![endif]-->
<source srcset="../examples/images/extralarge.jpg" media="(min-width: 1000px)">
<source srcset="../examples/images/large.jpg" media="(min-width: 800px)">
<!--[if IE 9]></video><![endif]-->
<img srcset="../examples/images/medium.jpg" alt="A giant stone face at The Bayon temple in Angkor Thom, Cambodia">
</picture>
Here's how that renders in the browser. Feel free to resize to see it change.