Various enhancements are -
In addition to specifying markup, HTML5 specifies scripting application programming interfaces (APIs). There are also new APIs, such as:
• The canvas tag for immediate mode 2D drawing
• Timed media playback
• Offline storage database
• Document editing
• Cross-document messaging
• Browser history management
• MIME type and protocol handler registration
HTML5 aims to reduce the need for proprietary plug-in-based rich Internet application (RIA) technologies such as Adobe Flash, Microsoft Silverlight and Sun JavaFX, though it would take many years to do so. HTML4 did not allow the embedding or control of multimedia content, whereas HTML5's new audio and video elements enable developers to embed and control multimedia content without Flash.
HTML5 features such as Canvas, local storage and Web Workers enable developers to leverage the browser in ways earlier technology did not allow. Opera Software has been viewed as a leader in implementing HTML5 technology in its browser.
HTML5 technologies such as Canvas, for 2D drawing on a Web page, are finding their way into offerings from companies like Apple, Google and Mozilla.
HTML5's local storage capability enables users to work in a browser when a connection drops, and the Web Workers technology makes applications responsive by pushing long-running tasks to the background.
All the major browser vendors-Mozilla, Opera, Microsoft, Apple and Google-are involved in shaping the HTML5 spec and are implementing support for it, despite the spec not being finalized.