Considering the practical application of the previous HTML versions in the terms of the everyday Internet usage, in particular HTML 4.01 and XHTML, HTML5 version gives the ability to affirm that they are the combination of characteristics of diverse specifications; in the common WWW use, this combination usage is equal to such software products, as the web browsers and the syntax errors that exist in the Internet documents. At the same time HTML5 is intended to create the single markup language regardless of the syntax it is written in. It possesses the elaborated processing models that are aimed at the perfection of the interoperable realization. This way, HTML5 serves the purpose of the expanding, upgrading and improvement of the markup that is appropriate for the documents and presents the markup and APIs that fit the complex Internet applications.
HTML5 provides the unique possibility to get the new characteristic components and elements that appear in the result of the modern websites usage. In the cases of the ordinary usage of the generic blocks and inline elements, the part of these components and elements serve the purpose of the semantic substitutions.
Besides, the HTML5 syntax is an independent syntax and has nothing to do with the SGML even regardless some resemblance of the markup. This peculiarity has intentionally been designed with the aim to provide the backward compatibility with the hierarchical analysis of the previous HTML versions. The new opening line of the HTML5 version, that has some similarities with the SGML document type declarative statement, corresponds to the rendering mode that fully meets the required standards. On January 5, 2009, the HTML5 developers implemented WHATWG specification, Web Forms 2.0, that had earlier been the separate specification.