HTML5 is the newest hyper text markup language for websites from the World Wide Web Consortium (W3C). The first draft was made public in 2008, but not much happened until 2011. In 2011, HTML5 was released and people started writing about it and using it. Today all major browsers (Chrome, Safari, Firefox, Opera, IE) offer HTML5 support, therefore the newest HTML technology can be used at its best today.
HTML5 is a markup language for structuring and presenting content for the World Wide Web and a core technology of the Internet. It is the fifth revision of the HTML standard (created in 1990 and standardized as HTML 4 as of 1997) and, as of December 2012, is a W3C Candidate Recommendation. Its core aims have been to improve the language with support for the latest multimedia while keeping it easily readable by humans and consistently understood by computers and devices (web browsers, parsers, etc.)
HTML5 works with CSS3 and is still in development. W3C plans to release a stable version next year, but it still looks like this is a long shot. Since its release, HTML5 has been in continuous development, with the W3C adding more and more impressive features, therefore it seems quite unlikely that HTML5's development will end soon, which is not necessarily a bad thing.
HTML5 - New Features
Some of the most interesting new features in HTML5:
— The <canvas> element for 2D drawing
— The <video> and <audio> elements for media playback
— Support for local storage
— New content-specific elements, like <article>, <footer>, <header>, <nav>, <section>
— New form controls, like calendar, date, time, email, url, search;
Web Workers: Certain web applications use heavy scripts to perform functions. Web Workers use separate background threads for processing and it does not effect the performance of a web page.
Video: You can embed video without third-party proprietary plug-ins or codec. Video becomes as easy as embedding an image.
Canvas: This feature allows a web developer to render graphics on the fly. As with video, there is no need for a plug in.
Application caches: Web pages will start storing more and more information locally on the visitor's computer. It works like cookies, but where cookies are small, the new feature allows for much larger files. Google Gears is an excellent example of this in action.
Geolocation: Best known for use on mobile devices, geolocation is coming with HTML5.