HTML5 is the first major update to the HTML standard since HTML4 was standardized in 1994. Full approval by standards bodies and complete implementation may take another decade, but parts of HTML5 are already being implemented.
Each browser supports HTML5 to a different degree. The www.html5test.com website can be used to test the extent to which a browser currently supports HTML5.
The screens to the right were taken from a test of a Droid X running Android version 2.3.3. It scored 177 points out of a total of 450. As is evident from this test, smartphone browsers are not very far along in implementing HTML5 features. The lower screen to the right shows the status of some desktop browsers.
Possibly the most well known of the HTML5 features is the new tag that will avoid the need for Flash in playing videos. This is especially important now that Adobe has announced it will stop development of Flash for mobile devices.
HTML5 contains many new features. A number of these are focused on eliminating the need for proprietary plugins and Application Programming Interfaces (APIs.) This advances the idea of being able to develop applications that will run on any device that supports HTML5, including multiple smartphone, tablet and desktop brands.