3 May 2011
Although the HTML 5.0 draft specification is not scheduled to become a standard until 2014, it is already a technology that is seeing wide adoption and creative use across the Internet. New ways to visualize, consume, and engage with information and media are made possible with this natural evolution of the HTML language. HTML5 is a versatile tool that can be used to accomplish tasks and present information throughout the Internet, consumable via numerous form factors and desktop and mobile devices alike.
This article provides an overview of HTML5—what it is and is not, why you should care about it, and how it may benefit you and change the way you will build web applications—and lists several resources that you can use to dive deeper into HTML5.
Like many people, you might still be wondering what HTML5 is exactly.
In the strictest sense, HTML is a text-based markup language used to format information that is often disseminated via the Internet. At a high level, HTML is a language that is used to structure and present text and images within a user interface. HTML5 is an augmentation of the current HTML 4.01 specification that adds new features that designers and developers will be able to use when creating their own content.
Some of the most notable changes in HTML5 are the addition of tags to support multimedia elements and dynamic graphics. This includes the
<audio> tag for playing sound, the
<video> tag for video playback, and the
<canvas> tag for dynamic graphics, all within the web browser, and without reliance upon external software. The new multimedia elements enable modern browsers to provide a rich experience and dynamic graphics from the HTML code. Whether using video, image manipulation, or data visualization, support for these elements enables designers and developers to create rich and engaging experiences that (the drivers behind HTML5 hope) will work reliably across all platforms.
Another capability that HTML5 brings to the table is the introduction of semantic markup tags. Semantic tags allow you to structure your HTML content so that the document structure provides semantics, or meaning, to the content. This includes the
<nav> , and
<figure> tags, which are used to create self-describing HTML documents. These allow you to denote which parts of the HTML document are for navigation, which are for layout, and which pieces of the document contain meaningful or related content. The new semantic tags enable a higher level of organization within a given HTML document, and can be used to create content that is more easily read by search engines, aggregators, or other content-consuming applications, thus further facilitating device-to-device communication, consumption of content, and information dissemination.
In addition to these features, HTML5 introduces a simpler DOCTYPE tag/syntax than previous iterations of HTML. The HTML doctype has been drastically simplified, and valid HTML5 documents are essentially valid XML structures. Previous iterations of HTML were based upon SGML (Standard Generalized Markup Language), which requires specific Document Type Definitions (DTDs) to validate proper document structure. With HTML5, content is XML based and must follow valid XML formatting rules. Even though HTML5 content doesn't require a DTD, the simpler
<!DOCTYPE HTML> must be required to ensure that browsers behave appropriately.
Although this isn't an exhaustive list of the changes coming with HTML5, it should give you an idea of what will be possible with the new standard. For full details of the latest changes regarding HTML5, be sure to check out the W3C published spec and changes from HTML4 online or browse the full HTML5 spec online.
In general, HTML5 is an evolution of the HTML language that is intended to bring richer, standards-based content to the web and the multidevice world. It is intended to simplify some of the complexities and structure of the current HTML 4.01 spec; enable easier creation and consumption of rich media, dynamic graphics, and complex user interfaces; and foster an environment where you can rely upon a consistent experience on all browsers and devices that support HTML5 capabilities. In essence, HTML5 promises to change the premise that HTML is just for static textual content. Web development paradigms are changing and HTML5 promises to become a platform for web programming, not just a markup language.
All of the latest major desktop browsers support HTML5 features in some fashion (although not all support HTML5 equally), and all of the leading smart phone and tablet devices support it as well. HTML5 can be a compelling solution for multidevice and multiscreen applications because of its already broad support. Not only is HTML5 an option for developing rich experiences in the browser, several desktop and tablet application vendors provide software development kits (SDKs) specifically targeting native application development purely using HTML5 syntax and structure.
Although HTML5 is not yet standardized, it can be used today. HTML5 is actively maturing, and is already a viable technology solution. Apple iOS, Android, BlackBerry 6, and HP/Palm WebOS devices all support HTML5 features, as do all of the latest desktop browser engines (Safari, Chrome, Opera, Internet Explorer). Currently, not all browsers have equal support of HTML5 features, so actual usage should be determined by your target users, platforms, and devices.
Discounting the relevance of HTML5 at this point would be a mistake. HTML5 can be a useful addition to your toolbox as a web developer. As technologies evolve so do the form and structure of how those technologies are implemented. HTML5 is intended to be future-proof. HTML documents created using the HTML5 doctype must follow XML/XHTML parsing rules and will be valid structures that should work indefinitely into the future, even as the language continues to evolve.
In addition, HTML5-based content will be easier to consume by content aggregators as well as an ever-growing array of devices. Today, you can consume HTML5-based content on your desktop computer, your phone, your tablet, and perhaps even your car. Developing content targeting the HTML5 standard can open unforeseen doors in the future. Who knows, perhaps tomorrow, your refrigerator, washing machine, or even gas pump may be consuming your HTML standards-based rich contents.
Here are a few useful HTML5 resources to get you started:
Also be sure to check out the Chrome Experiments, a showcase for web projects built with HTML5 and other technologies.