TABLE OF CONTENTS This Appendix gives a brief overview of the XML language and the reasons why it has been chosen as a file exchange format for IEC 61499 library elements, for example, for exchanging function block definitions between engineering support systems and other IEC 61499 compliant applications.
XML the next generation Web page markup language
The Extensible Markup Language (XML) has been derived as a subset of the generic ISO Standard Generalized Markup Language (SGML). XML is being developed as the next generation markup language to replace HTML, which is the language that is currently used for page content on the Internet World Wide Web.
SGML is a standard document formatting language that enables a publisher to create a single document source that can be viewed, displayed, or printed in a variety of different ways. However, SGML is a comprehensive language with a very complex format that is unsuitable, as it stands, for Web usage. Hypertext Markup Language (HTML) and XML are both simplified versions of SGML that that have been especially developed to create and view Internet Web pages. XML and HTML are both used to define how pages and graphics appear when viewed by Web Browsers. However, XML has an extensible range of features that will allow information to be accessed more quickly and displayed in different ways. XML is being developed to support applications that need to not only view document content but also to extract and manipulate information in a variety of different ways.
SGML related...
