HTML5 is the latest version of HTML, and although adoption on desktop browsers such as Internet Explorer is slow, mobile devices are jumping on the bandwagon in record numbers. Nearly every smartphone and tablet device sold today supports HTML5, and those numbers are growing.
In this hour you will learn how HTML5 came into being and how it has changed the landscape for web designers and developers as well as the customers viewing your pages. You’ll learn to build a simple HTML5 document and why HTML5 is the language you should know if you want to design and develop mobile applications.
Understanding How We Got to HTML5
In March 1989, Sir Tim Berners-Lee wrote a proposal that suggested using hypertext to link related documents together over a network. After collaborating with others at CERN, hypertext eventually became HTML or Hypertext Markup Language.
HTML was based on a language already in use for marking up documents—SGML (Standard Generalized Markup Language). In September 1991, a discussion began across the internet about how the web and HTML should evolve.
Up until around 1993, the only browser available was a text-only browser called Lynx. Then Mosaic came out with features such as images, nested lists, and forms. Most designers these days take these things for granted, but back in the early 1990s many people browsed the web in a black-and-white (or green-and-black), text-only environment. Getting a browser to support images was very exciting.
It wasn’t until 1994 that the HTML working group was set up by the IETF (Internet Engineering Task Force). In July it released a working draft of HTML 2. Later that year, the W3C, or World Wide Web Consortium, was formed at MIT to act as a standards body for HTML. HTML 3 was released as a draft in 1995, and HTML 3.2 was endorsed as a standard in 1997. HTML 4 was published as a recommendation in 1999.
XML and XHTML
After 1999 things began to change. The W3C no longer felt that HTML should remain as it was. Instead, they wanted to make it more machine-readable, more consistent, and much stricter. So, rather than working on a new version of HTML, they began turning HTML into a strict markup language called XHTML.
XHTML was created as a version of HTML 4.01 that was rewritten in XML (eXtensible Markup Language). It was developed in 1998 as a way to create markup languages that are machine readable. XHTML documents must be well formed and valid. In fact, the W3C wanted all browsers that read XHTML to stop rendering the page if the page’s HTML was not valid or well-formed.
XML is still used by many companies. For example, many content management systems (CMSs) use XML on the back end to manage large websites; many books are written in DocBook, which is an XML language for publishing; and ePub books use XML to create ebooks.
HTML5 is Born
XHTML, because it is based on XML, has the same strict requirements as XML, which makes XHTML very difficult to write. Although most web designers recognize the importance of creating HTML that is valid, at the end of the day the most important thing is that the HTML works in readers’ browsers. Every beginning web designer who has ever validated a page knows that just because a page isn’t valid doesn’t mean browsers won’t be able to display it. In fact, web browsers have no problem displaying technically invalid HTML.
Because of these difficulties, a group of web designers and developers as well as browser makers and others got together in 2004 and formed the Web Hypertext Application Technology Working Group (WHATWG). They started building the HTML5 specification to address the needs of designers, developers, and browser makers. Finally, in 2008, the W3C decided to scrap XHTML development in favor of reintegrating with the HTML5 community, and added the HTML5 specification into the W3C framework.