Semantically-Interlinked Online Communities. Strategies for Building Semantic Web Applications. Index of /hhalpin/homepage. Introducing Linked Data And The Semantic Web. Next: Introducing Graph Data What is Linked Data and the Semantic Web and what is all the hype about?
Principally, the Semantic Web is a Web 3.0 web technology - a way of linking data between systems or entities that allows for rich, self-describing interrelations of data available across the globe on the web. In essence, it marks a shift in thinking from publishing data in human readable HTML documents to machine readable documents. That means that machines can do a little more of the thinking work for us. How Does It Differ From The Web As It Is Today? Today, much of the data we get from the web is delivered to us in the form of web pages - HTML documents that are linked to each other through the use of hyperlinks. Enter Linked Data - Liberating Web Databases From Their Old Chains The web contains lots of information, but typically the raw data itself isn't available - rather only HTML documents constructed from data, if a web site is generated from a database at all.
But Where Do I Start? Publications of the W3C Semantic Web Activity. Resource Description Framework (RDF) Semantic technologies. RDF Vocabulary Description Language 1.0: RDF Schema. Abstract The Resource Description Framework (RDF) is a general-purpose language for representing information in the Web.
This specification describes how to use RDF to describe RDF vocabularies. This specification defines a vocabulary for this purpose and defines other built-in RDF vocabulary initially specified in the RDF Model and Syntax Specification. Contents 1. 1. The Resource Description Framework (RDF) is a general-purpose language for representing information in the Web. This specification is one of several [RDF-PRIMER] [RDF-SYNTAX] [RDF-CONCEPTS] [RDF-SEMANTICS] [RDF-TESTS] related to RDF. This specification introduces RDF's vocabulary description language, RDF Schema. This document is intended to provide a clear specification of the RDF vocabulary description language to those who find the formal semantics specification, RDF Semantics [RDF-SEMANTICS] daunting.
This document does not specify a vocabulary of descriptive properties such as "author". 2. 2.1 rdfs:Resource. Publications of the W3C Semantic Web Activity. A Direct Mapping of Relational Data to RDF. Status of this Document This section describes the status of this document at the time of its publication.
Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at This is a Public Working Draft of the "A Direct Mapping of Relational Data to RDF" for review by W3C members and other interested parties. This document was developed by the W3C RDB2RDF Working Group. Comments on this document should be sent to email@example.com, a mailing list with a public archive. Publication as a Working Draft does not imply endorsement by the W3C Membership. This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. 1 Introduction Relational databases proliferate both because of their efficiency and their precise definitions, allowing for tools like SQL [SQLFN] to manipulate and examine the contents predictably and efficiently. Resolution:
R2RML: RDB to RDF Mapping Language. This document describes R2RML, a language for expressing customized mappings from relational databases to RDF datasets.
Such mappings provide the ability to view existing relational data in the RDF data model, expressed in a structure and target vocabulary of the mapping author's choice. R2RML mappings are themselves RDF graphs and written down in Turtle syntax. R2RML enables different types of mapping implementations. Processors could, for example, offer a virtual SPARQL endpoint over the mapped relational data, or generate RDF dumps, or offer a Linked Data interface. 1 Introduction This specification describes R2RML, a language for expressing customized mappings from relational databases to RDF datasets.
This specification has a companion that defines a direct mapping from relational databases to RDF [DM]. Every R2RML mapping is tailored to a specific database schema and target vocabulary. R2RML mappings are themselves expressed as RDF graphs and written down in Turtle syntax [TURTLE].