XHTML5
Introduction
XHTML5 is a markup language that is used for structuring and presenting content on the World Wide Web. It is a revision of the Hypertext Markup Language (HTML), and is a combination of classic HTML and XML, which is a more stringent markup language. XHTML5 is part of the family of XML markup languages, which mirrors or extends versions of the widely used HTML.
History
XHTML5 is a response to the observation that HTML5 had, over time, drifted away from being a pure SGML application and had become a language of its own. The World Wide Web Consortium (W3C) began work on this new version of XHTML in 2007, but it was not until 2010 that the first public draft was released. The development of XHTML5 is being carried out in parallel with HTML5.
Syntax and Document Structure
The syntax of XHTML5 is very similar to that of HTML5, but it is stricter. For example, all elements must be properly nested, tags must be in lower case, and all tags must be closed. In addition, attribute values must always be quoted, and attribute minimization is forbidden.
The document structure of an XHTML5 document is also similar to that of an HTML5 document. It consists of a DOCTYPE declaration, a root element, a head element, and a body element. However, there are some differences. For example, the DOCTYPE declaration in XHTML5 is simpler than in HTML5. In XHTML5, it is simply "<!DOCTYPE html>", whereas in HTML5, it is "<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">".
Advantages and Disadvantages
One of the main advantages of XHTML5 is that it is more rigorous than HTML5. This means that it is less prone to errors and is more predictable. It is also more compatible with XML parsers, which makes it easier to integrate with other XML-based technologies.
However, there are also some disadvantages to using XHTML5. One of the main disadvantages is that it is less forgiving than HTML5. This means that if there is a mistake in the markup, the browser will stop parsing the document. In contrast, HTML5 is designed to be more forgiving and will continue to parse the document even if there are errors.
Compatibility
XHTML5 is designed to be backwards compatible with both HTML4 and XHTML1. This means that documents written in these older versions of HTML can be converted to XHTML5 without losing any functionality. However, there are some differences in the way that certain elements and attributes are handled in XHTML5 compared to HTML4 and XHTML1.
Future of XHTML5
The future of XHTML5 is uncertain. While it has some advantages over HTML5, it also has some disadvantages. In addition, the adoption of XHTML5 has been slow, and many web developers prefer to use HTML5 because it is more forgiving and easier to use. However, XHTML5 is still being developed and improved, and it is possible that it will become more popular in the future.