HTML5 is the set of technology standards that support the next phase in the development of the Web. From its beginning, Mozilla has championed Web standards to ensure freedom of choice for those who use the Web and independence for those who build it. Leaders from Mozilla helped start the evolution of HTML and related standards that is now known as HTML5, and Mozilla continues to lead in both defining and implementing these standards.
The term “HTML5” has been applied to many things, creating confusion about exactly what it is and what it can do. Rather than split hairs, we use “& friends” to encompass all the “new, exciting Web technologies” that will enable the next wave of Web-based innovation.
Cascading Style Sheets deliver a wide range of stylization and effects, enhancing web pages without sacrificing their semantic structure or performance. CSS3 is the latest version of the CSS standard, introducing exciting new effects like dynamic color gradients, 2D and 3D transforms, multi-column and flexible layouts, calculations, transitions, animations, and media queries to tailor different styles for different devices.
Not technically part of HTML5, CSS3 is a separate — though closely connected — set of standards, emerging and evolving in tandem with HTML5.
HTML5 introduces a number of new elements and attributes to support content in more meaningful ways. New form elements enhance interactivity with web apps. Together with RDFa, microdata, and microformats, HTML5 is enabling a more useful, data-driven Web for developers and users alike.
More efficient connectivity means more real-time chats, faster games, and better communication. WebSockets and Server-Sent Events are pushing (pun intended) data between client and server more efficiently than ever before.
Performance & Integration
Make apps more seamless and make dynamic content load faster with a variety of techniques and technologies such as Web Workers, XMLHttpRequest Level 2 (the technology behind Ajax), and the History API.
Offline & Storage
Web apps can still function even if there is no internet connection, thanks to the HTML5 App Cache, as well as the Local Storage, Indexed Database, and the File API specifications. Web apps can also load faster and respond more quickly when some of their vital data is locally stored by the client.
Incorporating audio or video into a web page has long required an additional plug-in to add more capabilities to the browser that weren’t native to the browser itself, but that’s changing with HTML5. The new audio and video elements allow web developers to embed sound and moving pictures into web pages without any proprietary plug-ins and let media interact with other web content in ways that weren't previously possible.
3D, Graphics, & Effects
Images on the Web have always been flat and static, created once and then living forever in a permanent, unchanging, 2-dimensional state. Now SVG and canvas can generate dynamic, interactive drawings, rendered on the fly in the browser. With canvas and WebGL, along with CSS3 3D transforms, flat vector shapes can be brought to 3-dimensional life, adding a new perspective (literally) to web imagery.
The Web is becoming more mobile every day, with an ever-growing number and variety of devices accessing it. With new technologies like the Geolocation API and touch events, web applications can present rich, device-aware features and experiences to rival native apps on the latest tablets and smartphones. Incredible device access innovations are being developed and implemented, from audio/video input access to microphones and cameras, to local data such as contacts & events, and even tilt orientation.