On the standards track: No
Is Experimental: No
Is Deprecated: No
Not in Chrome
Not in Chrome Android
Not in Edge
In Firefox version 4 on 2011-03-22
In Firefox for Android version 4 on 2011-03-29
In Internet Explorer version 5 on 1999-03-18
Not in Quest Browser
Not in Opera
Not in Opera Android
Not in Safari
Not in Safari on iOS
Not in Samsung Internet
Not in WebView Android