LOS! @ISWC2010

co-located with the 9th International Semantic Web Conference (ISWC2010), November 7-11, 2010
Date: November 8, 2010 - Venue: Shanghai, China

Linked Open Services (LOS) are a radical re-evaluation of the means to produce, describe and compose services on the Semantic Web. They harness the technologies favoured by Linked Data - RDF, SPARQL and HTTP - rather than imposing rule languages, SOAP and WSDL. Like Linked Data, and unlike traditional Semantic Web Services, they aim towards contribution to the knowledge on the Semantic Web. They are open in the sense that they are openly exposed, using only the Web as a platform, not hidden away inside closed services infrastructures. To these ends Linked Open Services are based, like Linked Data, on a simple set of principles to be explored, refined and supported in an open, community-driven manner.

Overview

In the form of ‘Semantic Web Services’, the combination of semantic technology and Web Services has been oriented towards extending the WS-* stack with ontology-based descriptions. At the same time, there is a strong movement away from this stack – for which the ‘Web’ part is little more than branding – towards a RESTful model of services.

The Linked Open Data (LOD) initiative is a prominent adopter of this approach and exposes many datasets via SPARQL endpoints and RESTful services. The developing model of Linked Open Services accommodates LOD endpoints and general RESTful services alongside WS-* stack based services with descriptions based on RDF and SPARQL. This capitalises on the Linked Open Data Cloud and makes service description and comprehension more easy and direct to the growing Linked Data community.

This LOS approach notes that the existing link between service messaging and the semantic viewpoint, commonly called `lifting and lowering', is usually unduly restricted to ontology-based classification and misses how the effect of a service contributes to the knowledge of its consumer. A novel SPARQL-based approach instead helps in the composition of services as processes that enhance the Semantic Web by making such knowledge available, and encourages the development and exposure of services that communicate RDF per default.

Tutors

Barry Norton
Institute AIFB / Karlsruhe Services Research Institute
Karlsruhe Institute of Technology, Germany
Reto Krummenacher
STI Innsbruck
University of Innsbruck, Austria

Tutorial schedule

As a half-day tutorial, the following material will be presented in Shanghai:

9:00 - 9:45	Introduction and Technical Overview	pdf
9:45 - 10:00	Technical Fundamentals	pdf
	RDF 101
10:00 - 10:30	Coffee break
10:30 - 11:00	Technical Fundamentals (cont.d)
	SPARQL 101, HTTP 101, REST 101
11:00 - 11:15	Wrapping services as LOS	pdf
11:15 - 11:50	Hands-On Session: Exposing Yelp services as LOS	pdf zip
11:50 - 12:10	Implemention: resource-oriented LOS	pdf
12:10 - 12:30	Conclusions and Future Directions	pdf

Prerequisites

Some familiarity with semantic technologies is a must, but any degree of preconception about services will be challenged (making unfamiliarity a potential advantage).

Links and background reading

	LOS! Blog
	LOS! Wiki