HTML5 is the Blueprint of the Future.

Introducing HTML 5

3-d futuristic boxes

What it is and why we should care

Why should we care you may ask? Because it is the evolution of a much larger specification that includes and merges HTML4, XHTML and the Dom Level Two. XHTML version Two, as a spec, has been dropped. Read about it in Dot Net magazine. (.net Magazine, Article: HTML5 Today, Dated 12/05/10)

With HTML5, one doctype - with no DTDs are required and it uses simplified character encoding (UTF-8). The style and script elements in HTML5 no longer need the type attribute as they default to text/css and text/javascript respectively. There is also the Web Forms 2.0 spec in HTML5, which means JavaScript is not necessary to do basic form validation.

HTML5 removes or re-defines presentational markup and offers the addition of new semantic elements for organizing content. The HTML5 specification also includes formulated foundation level Application Programming Interfaces. Some examples include:  audio & video,  inline editing,  dragging & dropping,  offline applications  the canvas element,  history,  and web protocol.

See a Presentation of HTML5 planned specs at HTML5Rocks.com

What it is not

It is not CSS3 Transitions, Web Sockets, Geolocation, Scaleable Vector Graphics(SVG), or CSS3 @font-face.

WebSocket is a technology providing for bi-directional, full-duplex communications channels, over a single Transmission Control Protocol (TCP) socket. It is designed to be implemented in web browsers and web servers but it can be used by any client or server application.

*Web sockets, Geolocation, and scalable vector graphics are classified as Associated Application Programming Interfaces (AAPI). Transitions and @font-face are new modules defined by the new CSS3 specifications.