HyperText Markup Language (HTML) is the basic language of the Web. This language is constantly evolving, and HTML5 (note there is no space in HTML5) is the newest major revision. It drops some elements from version 4 and introduces new ones to take advantage of how modern Web developers work in Web 2.0.
Development of HTML5 began in 2004 but may not be completed until 2022 or later, according to the Web Hypertext Application Technology Working Group (WHATWG). This does not mean HTML5 will be unavailable for use until then. On the contrary, as various elements are standardized, browsers will be updated to support them, and developers will start experimenting with them.
Some of the new features, already supported by several browsers, include:
- Structural elements to define different parts of a page: For example, article, footer and header (not the page header, but headers for sections and articles)
- Offline data storage
- Cross-document messaging
The really exciting news surrounding <video> is that browsers will eventually be able to read the file without using a plug-in. To view Web video today you must install a piece of software, usually Flash, that runs in your browser but is not actually a part of it. These plug-ins have improved in recent years, but are still prone to crashing and using excess CPU resources.
Browsers supporting HTML5 will come with video decoding software prepackaged, greatly improving stability, although browser vendors have yet to agree on a standard decoding software. For now, you can embed video using the <video> tag now, but browsers will still need a plug-in to read the file.
HTML5 and The Mobile Web
HTML5 is seen as critical to mobile development, as many device makers limit the apps, like Flash or Java, that can run on their devices. HTML5 does not require these plug-ins, and the WebKit-based browsers on many smartphones already support much of HTML5. So mobile technology is well positioned to deliver a richer interactive Web experience with HTML5.
Development on HTML5 has a long way to go, but designers and developers should be experimenting now. The average business owner doesn’t need to worry about it yet, but if you are redesigning your site, consider defining your doctype according to HTML5 standard and using those structure elements already supported to make future enhancements easier to implement.