computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...

, Resource Directory Description Language (RDDL) is an extension of

XHTML Extensible HyperText Markup Language (XHTML) is part of the family of XML markup languages. It mirrors or extends versions of the widely used HyperText Markup Language (HTML), the language in which Web pages are formulated. While HTML, prior ...

Basic 1.0. An RDDL document, called a Resource Directory, provides a package of information about some target. The targets which RDDL was designed to describe are

XML namespace XML namespaces are used for providing uniquely named elements and attributes in an XML document. They are defined in a W3C recommendation. An XML instance may contain element or attribute names from more than one XML vocabulary. If each vocabulary ...

s. The specification for RDDL has no official standing and has not been considered nor approved by any organization (e.g., W3C). RDDL is designed to allow both human readers and software robots to find any sort of resource associated with a particular namespace. Instead of putting one thing at the end of a namespace

URI Uri may refer to: Places * Canton of Uri, a canton in Switzerland * Úri, a village and commune in Hungary * Uri, Iran, a village in East Azerbaijan Province * Uri, Jammu and Kashmir, a town in India * Uri (island), an island off Malakula Islan ...

, RDDL puts a document there that lists all the machine-processable documents that might be available, including: *

Document Type Definition A document type definition (DTD) is a set of ''markup declarations'' that define a ''document type'' for an SGML-family markup language ( GML, SGML, XML, HTML). A DTD defines the valid building blocks of an XML document. It defines the document ...

s (DTD) *

XML schema An XML schema is a description of a type of Extensible Markup Language, XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed ...

s in a variety of languages (including

RELAX Relax may refer to: Aviation * Roland Z-120 Relax, a German ultralight aircraft design for the 120 kg class Music Albums * ''Relax'' (Blank & Jones album), 2003 * ''Relax'' (Das Racist album), 2011 Songs * "Relax" (song), a 1983 song by Fran ...

Schematron Schematron is a rule-based validation language for making assertions about the presence or absence of patterns in XML trees. It is a structural schema language expressed in XML using a small number of elements and XPath. In many implementations ...

W3C XML Schema XSD (XML Schema Definition), a recommendation of the World Wide Web Consortium (W3C), specifies how to formally describe the elements in an Extensible Markup Language (XML) document. It can be used by programmers to verify each piece of item cont ...

, TREX, and others) *

Cascading Style Sheets Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone techno ...

XSLT XSLT (Extensible Stylesheet Language Transformations) is a language originally designed for transforming XML documents into other XML documents, or other formats such as HTML for web pages, plain text or XSL Formatting Objects, which may subseque ...

, and other style sheet specifications * Specification documents

rddl:resource

An RDDL document identifies each related resource by a resource element in the http://www.rddl.org/ namespace, which is customarily mapped to the rddl prefix. This element is a simple

XLink XML Linking Language, or XLink, is an XML markup language and W3C specification that provides methods for creating internal and external links within XML documents, and associating metadata with those links. The XLink specification XLink 1.1 is a ...

(that is, it has an xlink:type attribute with the value simple) and its xlink:href attribute points to the related resource. Furthermore, the xlink:role attribute identifies the nature of the related resource and the optional xlink:arcrole attribute identifies the purpose of the related resource. An optional xlink:title attribute can provide a brief description of the purpose of the link.

External links

RDDL home page
HTML {{compu-lang-stub