XML Glossary

An industry initiative started by Microsoft and supported by a wide range of organizations. BizTalk is a community of standards users, whose goal is the adoption of XML in electronic commerce and application integration through the BizTalk Framework, a set of guidelines for how to publish schemas in XML.

CDF (Channel Definition Format)
Microsoft's XML-based file format for the description of channel information.

CSS (Cascading Style Sheets)
A means of defining certain document elements (paragraphs, headings, fonts, colors, positioning, backgrounds) with style rules instead of additional markup tags.

DOM (Document Object Model)
A platform- and language-neutral interface that allows scripts and programs to access and update dynamically the content, structure, and style of documents. It provides a standard set of objects for representing HTML and XML documents, a model of how these objects can be combined, and an interface for accessing and manipulating them.

DTD (Document Type Definition)
The rules that define the tags that can be used in an XML file and their valid values.

EDI (Electronic Data Interchange)
The electronic communication of business transactions between organizations. XML complements EDI because it can be used to exchange e-commerce information.

gXML (Guideline XML)
A file structure supported by EDI software company Edifecs Commerce that allows the open exchange of electronic commerce guidelines.

HTML (HyperText Markup Language)
A nonproprietary methodology for creating Web pages. HTML defines the page layout, fonts, graphic elements, and hypertext links to other Web documents by embedding tags (codes) within the text.

HyTime (Hypermedia/Time-based Structuring Language)
A language that specifies the hypermedia structure of documents.

IETF (Internet Engineering Task Force)
An organization of working groups that identifies problems and proposes technical solutions for the Internet. They publish XML-related RFCs (Requests for Comments) and specifications.

An integrated set of C++ and Java-based XML tools from the Language Technology Group for processing XML documents.

A proposal for XML namespaces (groups of names defined according to some naming convention) that ensures that names remain unambiguous even if chosen by more than one author.

MathML (Mathematical Markup Language)
An XML methodology for describing mathematical notations on the Web, just as HTML does for ordinary text.

Data that describes other data. Metadata about an XML document is described in the DTD or in the XML document itself, enabling other applications to interact with it.

A language that describes other languages. SGML and XML can be considered metalanguages because they define markup languages.

OASIS (Organization for Advancement of Structured Information Systems)
A consortium of companies and individuals that collects and publishes XML specifications, DTDs, and schemas. By standardizing specifications, OASIS hopes to advance the open interchange of documents and structured information objects.

OSD (Open Software Description) Format
An XML-based specification designed by Microsoft and Marimba to automate software distribution. OSD uses unique XML tags to describe software packages.

RDF (Resource Description Framework)
A model for describing and interchanging metadata. It allows a Web site to describe its dynamic (user-created) content without having to store static pages that contain that content.

RFC (Request for Comments)
A document used by the IETF to describe the specifications for a recommended technology.

A system of representing a data model that defines the data's elements and attributes, and the relationship among elements.

SGML (Standard Generalized Markup Language)
The "mother of all markup languages," it's a metalanguage used to construct other markup languages. XML is designed to be "an ex-tremely simple dialect of SGML" (per the W3C XML specs) for the Web.

SMIL (Synchronized Multimedia Integration Language)
A language designed to integrate multimedia objects into a synchronized presentation.

A superset of the ASCII character set, this 16-bit character encoding scheme includes not only the standard Roman and Greek alphabets, but also mathematical symbols, special punctuation, and non-Roman character sets (Hebrew, Chinese, etc.).

URI (Uniform Resource Identifier)
The addressing technology by which URLs (Uniform Resource Locators) are created. Technically, http:// and ftp:// are specific subsets of a URI.

XFRML (Extensible Financial Reporting Markup Language)
The new "digital language of business" supported and proposed by the American Institute of Certified Public Accountants, which allows the financial community to exchange and analyze a variety of financial reports. Still a work in progress.

XHTML (Extensible HyperText Markup Language)
The "XML-ization of HTML"—essentially the "newest version" of HTML, which extends its functionality to support a wider range of devices and applications.

A package of hyperlinking functionality that comes in two parts. "XLink" governs how links are inserted into an XML document; "XPointer" determines the identifier that goes on a URL when linking to an XML document from somewhere else, such as another Web page. Formerly known as XLL (Extensible Linking Language).

XLL (Extensible Linking Language)
The standard for describing links among objects in XML documents. (See XLink.)

XMI (XML Metadata Interchange)
An open information interchange model intended to give developers working with object technology the ability to exchange programming data over the Internet in a standardized way, bringing consistency and compatibility to applications created in collaborative environments. XMI is intended to be either stored in a traditional file system or streamed across the Internet from a database or repository.

XML (Extensible Markup Language)
A data format for structured document interchange that is more flexible than HTML. While HTML's tags are predefined, XML allows tags to be defined by the developer of the page. Thus, XML-defined Web pages can function like database records.

XML dialect
Any "flavor" of XML defined by a DTD that is designed to support a specialized purpose, such as BIOML (BIOpolymer Markup Language), CML (Chemical Markup Language), MathML, CDF, TalkML (an experimental XML for voice browsers), XFRML, etc.

XML editors
Software that allows basic data/metadata editing functions and explicit control over XML markup. Products run the gamut from simple editors for small documents, such as Language Technology Group's XED, to more full-featured XML "word processors," such as Icon's XML Spy, Vervet Logic's XML Pro, and SoftQuad's XMetaL.

XML entities
Special sets of characters that help expand document content without increasing the overall character count. Internal entities act as typing shortcuts or macros; external entities incorporate content from outside sources into the main document.

XML namespace
A way of defining each element type and attribute name in an XML document unambiguously (through associations with specific URIs) so that two or more XML-based languages may be used in that document without creating a conflict.

XML processor
A software module that reads XML documents and provides access to their content and structure. The processor does its work on behalf of another module, called the application. The processor reads the XML data and provides the application with the information.

XML-QL (XML Query Language)
A query language for XML, which, like SQL, has a SELECTWHERE construct and uses features of query languages developed for semi-structured data. XML-QL is a competing proposal to XPath, but is not likely to be adopted as a recommendation by the W3C.

XMOP (XML Metadata Object Persistence)
A set of components that allows the interoperation between object technologies such as Java, Microsoft COM, and CORBA. This means that objects can be transported between different object systems (COM and Java) and different Java VMs (Microsoft's and Sun's).

XPath (XML Path Language)
A way of referencing information within an XML document, intended as a bridge between XPointer and XSLT. XPath uses a directory notation to perform queries through the selectNodes architecture and lets you determine which elements within an XML document satisfy a given set of criteria.

XSL (Extensible Style Language)
The style standard for XML. Like CSS, it specifies the presentation and appearance of an XML document.

XSLT (XSL Transformations Language)
A language used to transform (reformat) XML documents into other XML documents. XSLT supports both push and pull transformations and is designed to be used independently of XSL; however, it is not intended to function as a general-purpose XML transformation language.