History of HTML
During the 1990's, the HTML standard had been evolving pretty steadily. But as Internet Explorer, with it's non-standard extensions, gained popularity with developers it caused a divergence between the standard and the implementation, which resulted in the evolution of the markup language becoming stagnant for almost a decade. Attempt to make some additional improvements in HTML, as xHTML, unfortunately backfired and resulted in further chaos in HTML development.
Finally, HTML version 5 promises to bring order back to the chaos. There is enough support from vendors and standards bodies behind HTML 5 that developers who have been creating web sites using HTML and xHTML as well as Flash can confidently start their migration to this latest version of HTML. Many web browsers, including Chrome, Firefox, Opera and Safari already support many of the features of HTML 5. In particular, developers who are concerned about their web site content and apps running on mobile devices should start their migration to HTML 5.
New Features of HTML 5
- Style of web page elements
- HTML 5 continues to promote the separation of the semantic content of documents from the style of presentation of elements on web pages. Many of the HTML tags deprecated in this version were non-semantic tags which provided only some specific styling of web page elements.
- Separation of main content and navigation
- Earlier versions of HTML were not designed with accessibility in mind. Web page designers created some workarounds such as "Skip Navigation" links (similar to "Skip Intro" buttons), which would be placed near the beginning of web pages to allow users "viewing" a site with an HTML screen reader to keep the software from having to vocalize the navigation links on every page.
- HTML 5 continues to support XSL style sheets, which allow the navigation and other common elements to be completely removed from the documents with the main content and placed in one or more style sheet documents. The advantages of separating the navigation from the main content include:
- making the web pages more accessible, by not forcing screen readers to vocalize all of the navigation links before getting to the main content
- centralizing the "look and feel" of the web site using the templates in the style sheet documents
- improving page load times, since the style sheet documents can be cached by the browser and downloaded just once as opposed to when the common navigation elements are wrapped around the content and downloaded again and again with every web page
- making the web pages more mobile-friendly