| Introduction to XML |
| The eXtensible Markup Language (XML) is a general-purpose markup language. Its primary purpose is to facilitate the sharing of data across different information systems, particularly via the Internet. So, please get your fact right about XML, XML is meant for data exchange not for data storage. |
| XML is a simplified subset of the Standard Generalized Markup Language (SGML), and is designed to be relatively human-legible. By adding semantic restraints, application languages can be implemented in XML. These include XHTML, RSS, MathML, GraphML, Scalable Vector Graphics(SVG), MusicXML, and thousands of others. Moreover, XML is sometimes used as the specification language for such application languages. There are thousands of languages based on XML. |
| XML is nothing by itself. XML is more of a “common ground” standard. The main benefit of XML is that you can take data from a program like MSSQL(Microsoft SQL) or MySQL, convert it into XML, then share that XML with a slough of other programs, platforms, etc. Each of these receiving platforms can then convert the XML into a structure the platform uses normally and presto! you have just communicated between two potentially very different platforms! |
| What makes XML truly powerful is the acceptance and hard work done by all those who work with databases, programming, office application, etc. It is because of this hard work that the tools exist to do these conversion from whatever platform into standardized XML data or convert XML into a format used by that platform. |
| In the past, attempts at creating a standardized format for data that could be interpreted by many different platforms (i.e. different applications) failed miserably where XML has largely succeeded. |
| What is XML? |
| • XML stands for EXtensible Markup Language |
| • XML is a markup language much like HTML. |
| • XML was designed to describe data. |
| • XML tags are not predefined in XML. You must define your own tags. |
| • XML is self describing. |
| • XML uses a DTD (Document Type Definition) to formally describe the data. |
| XML is extensible |
| XML allows the author to define his own tags and his own document structure. The tags used to markup HTML documents and the structure of HTML documents are predefined. The author of HTML documents can only use tags that are defined in the HTML standard. |
| It is important to understand that XML is not a replacement for HTML. In the future development of the Web it is most likely that XML will be used to structure and describe the Web data, while HTML will be used to format and display the same data. |
| XML usage |
| Although there are countless of applications that use XML, here are a few examples of the current platforms and applications that are making use of this technology. |
| Cell Phones |
| XML data is sent to some cell phones, which is then formatted by the specification of the cell phone software designer to display text, images and even play sounds! |
| File Converters |
| Many applications have been written to convert existing documents into the XML standard. An example is a PDF to XML converter. |
| VoiceXML |
| Converts XML documents into an audio format so that you can listen to an XML document. |
| And many more….. |
| “XML is the future for all data transmission and data manipulation over the Web.” |