A linked data compliant framework for dynamic and web-scale consumption of web services

The While Semantic Web Services (SWS) research aims at automating Web service tasks such as discovery, orchestration and execution, its take-up is very limited so far. This is due to several reasons, such as inherent complexity of existing SWS frameworks and the considerable costs involved in creating correct SWS descriptions. In addition, while semantics are in use to enable tasks such as discovery, interaction between service consumers, providers and brokering environments is still not supported by semantic message descriptions. On the other hand, the Linked Data approach has produced a set of established principles for sharing and describing data, such as RDF as representation language and the integral use of dereferencable URIs. In this paper we propose to apply those principles to expose Web services and Web APIs and introduce a framework in which service registries as well as services contribute to the automation of service discovery, and hence, workload is distributed more efficiently. This is achieved by developing a Linked Data compliant Web services framework with that communicate with semi-centralised registries but compute their suitability for a given request themselves. All communications among different framework components are using RDF-based message protocols including service input and output. This framework aims at optimizing load balance and performance by dynamically assembling services at run time in a massively distributed Web environment

Services and the Web of Data: an unexploited symbiosis

The Web of Data is certainly a great success for data publication but the state of the art of the applications processing linked data is however not that outstanding. In this paper we highlight an unexploited symbiosis between Semantic Web Services and the Web of Data that could give birth to new families of highly advanced Web applications

A linked data-driven & service-oriented architecture for sharing educational resources

The two fundamental aims of managing educational resources are to enable resources to be reusable and interoperable and to enable Web-scale sharing of resources across learning communities. Currently, a variety of approaches have been proposed to expose and manage educational resources and their metadata on the Web. These are usually based on heterogeneous metadata standards and schemas, such as IEEE LOM or ADL SCORM, and diverse repository interfaces such as OAI-PMH or SQI. Also, there is still a lack of usage of controlled vocabularies and available data sets that could replace the widespread use of unstructured text for describing resources. On the other hand, the Linked Data approach has proven that it offers a set of successful principles that have the potential to alleviate the aforementioned issues. In this paper, we introduce an architecture and prototype which is fundamentally based on (a) Linked Data principles and (b) Service-orientation to resolve the integration issues for sharing educational resources

WSMO-Lite and hRESTS: lightweight semantic annotations for Web services and RESTful APIs

Service-oriented computing has brought special attention to service description, especially in connection with semantic technologies. The expected proliferation of publicly accessible services can benefit greatly from tool support and automation, both of which are the focus of Semantic Web Service (SWS) frameworks that especially address service discovery, composition and execution. As the first SWS standard, in 2007 the World Wide Web Consortium produced a lightweight bottom-up specification called SAWSDL for adding semantic annotations to WSDL service descriptions. Building on SAWSDL, this article presents WSMO-Lite, a lightweight ontology of Web service semantics that distinguishes four semantic aspects of services: function, behavior, information model, and nonfunctional properties, which together form a basis for semantic automation. With the WSMO-Lite ontology, SAWSDL descriptions enable semantic automation beyond simple input/output matchmaking that is supported by SAWSDL itself. Further, to broaden the reach of WSMO-Lite and SAWSDL tools to the increasingly common RESTful services, the article adds hRESTS and MicroWSMO, two HTML microformats that mirror WSDL and SAWSDL in the documentation of RESTful services, enabling combining RESTful services with WSDL-based ones in a single semantic framework. To demonstrate the feasibility and versatility of this approach, the article presents common algorithms for Web service discovery and composition adapted to WSMO-Lite

Supporting the creation of semantic RESTful service descriptions

Research on semantic Web services (SWS) has been devoted to reduce the extensive manual eort required for manipulating Web services by enhancing them with semantic information. Recently, the world around services on the Web, thus far limited to "classical" Web services based on SOAP and WSDL, has significantly evolved with the proliferation of Web applications and APIs, often referred to as RESTful Web services. However, despite their success, RESTful services are currently facing similar limitations to those identified for traditional Web service technologies and present even further difficulties, such as the lack of machine-processable service descriptions. In order to address these challenges and to enable the wider adoption of RESTful service technologies, we advocate an integrated lightweight approach for formally describing semantic RESTful services. The approach is based on the use of the hRESTS (HTML for RESTful Services) and MicroWSMO microformats, which enable the creation of machine-readable service descriptions and the addition of semantic annotations, correspondingly. Finally, we present SWEET - Semantic Web sErvices Editing Tool - which effectively supports users in creating semantic descriptions of RESTful services based on the aforementioned technologies

Toward the Next Wave of Services: Linked Services for the Web of Data

It has often been argued that Web services would have a tremendous impact on the Web, as a core enabling technology supporting a highly efficient service-based economy at a global scale. However, despite the outstanding progress in the area we are still to witness the application of Web services in any significant numbers on the Web. In this paper, we analyse the state of the art highlighting the main reasons we believe have hampered their uptake. Based on this analysis, we further discuss about current trends and development within other fields such as the Semantic Web and Web 2.0 and argue that the recent evolution provides the missing ingredients that will lead to a new wave of services - Linked Services - that will ultimately witness a significant uptake on a Web scale. Throughout the presentation of this vision we outline the main principles that shall be underpinning the development of Linked Services and we illustrate how they can be implemented using a number of technologies and tools we have developed and are in the process of extending

iServe: a linked services publishing platform

Despite the potential of service-orientation and the efforts devoted so far, we are still to witness a significant uptake of service technologies outside of enterprise environments. A core reason for this limited uptake is the lack of appropriate publishing platforms able to deal with the existing heterogeneity in the service technologies landscape and able to provide expressive yet simple and ecient discovery mechanisms. In this paper we describe iServe, a novel and open platform for publishing services which aims to better support their discovery and use. It exposes service descriptions as linked data expressed in terms of a simple vocabulary for describing services of different kinds with annotations in diverse formalisms. In addition to describing iServe, this paper also highlights the set of principles behind iServe, which we believe are essential for other generic repositories of semantic information notably ontology repositories

Using semantics for automating the authentication of Web APIs

Recent technology developments in the area of services on the Web are marked by the proliferation of Web applications and APIs. The implementation and evolution of applications based on Web APIs is, however, hampered by the lack of automation that can be achieved with current technologies. Research on semantic Web services is there fore trying to adapt the principles and technologies that were devised for traditional Web services, to deal with this new kind of services. In this paper we show that currently more than 80% of the Web APIs require some form of authentication. Therefore authentication plays a major role for Web API invocation and should not be neglected in the context of mashups and composite data applications. We present a thorough analysis carried out over a body of publicly available APIs that determines the most commonly used authentication approaches. In the light of these results, we propose an ontology for the semantic annotation of Web API authentication information and demonstrate how it can be used to create semantic Web API descriptions. We evaluate the applicability of our approach by providing a prototypical implementation, which uses authentication annotations as the basis for automated service invocation

Adding semantic annotations into (Geospatial) RESTful services

In this paper the authors present an approach for the semantic annotation of RESTful services in the geospatial domain. Their approach automates some stages of the annotation process, by using a combination of resources and services: a cross-domain knowledge base like DBpedia, two domain ontologies like GeoNames and the WGS84 vocabulary, and suggestion and synonym services. The authors’ approach has been successfully evaluated with a set of geospatial RESTful services obtained from ProgrammableWeb.com, where geospatial services account for a third of the total amount of services available in this registry