The SWAD-Europe workplan describes the structure of the overall project. This page provides the current state of the Semantic Web tools support in SWAD-Europe, which encompasses work in several workpackages: WP7, WP10, WP12.4.
This area of the SWAD-Europe project encompasses several different strands, including software development, surveys of existing work, and input into standards track work in the RDF Core and Data Access Working Groups at W3C.
The aim was to build on existing work and experience in the Semantic Web community and within the project to help get various data access methods for RDF (APIs and query languages) to the stage where they could be standardized. To do this, the project undertook surveys of existing APIs and query languages, implementations of RDF query languages, including testcases; and demonstrators showing scalability of the technologies. The focus was on near-term practical goals and grounding in running code. This work has fed directly into the W3C's Data Access working group.
This area of work researches the storage API requirements for RDF applications. Such APIs are required to access Semantic Web data stored within various kinds of RDF-aware system. They can be very low-level or more like query languages in their expressivity. Existing experience shows that that different sorts of RDF datastore will have different levels of API, and some datastores may implement several layers. Work here connects closely with the W3C RDF Core working group decisions and constraints on the RDF model; some deployed RDF APIs may not yet precisely reflect the clarifications of RDF produced by the RDF Core Working Group. This report looks at RDF features as expressed by the existing round of Working Drafts produced by the RDF Core Working Group and should provide a framework for the comparison of APIs and their associated semantics. "Sticking points" and potential problem areas are highlighted. The intention is to provide a reasonable basis for the evaluation of existing and future RDF APIs.
Last updated: 2003-02-27
This report is intended to compare existing RDF query language functionality, documenting different scenarios and users for RDF query languages (for example scripters, programmers; data, schema). There are many existing documents covering this area. Rather than repeating work that has already been done we have concentrated on frequently asked questions (FAQs)
Last updated: 2003-04-01
This report surveys the state of semantic web storage for RDF / triple data using existing free software tools. It takes a practical approach by targeting the work to the needs of developers, answering frequently asked questions related to this subject. The report first reviews previous work in surveying semantic web data, schema and triple stores, then gives an overview of the major systems with their feature set and maturity and then uses that information to provide a set of FAQs with answers related to storing semantic web data.
Last updated: 2002-07-31
This report surveys the schemas used in mapping between Semantic Web data and relational databases, and discusses mapping approaches to and from relational schemas. It describes current best practice for using such systems for Semantic Web data including feature comparisons, recommendations for particular applications and advice on tradeoffs.
Last updated: 2003-01-23
A Free Software/Open Source RDF storage system written in C together with documentation on implementation issues found; the report is written for a developer audience.
Last updated: 2003-03-07; Dave Beckett continues to work on the Redland software described in this report.
A description of work to implement an RDF query language in the Redland Application Framework and experiences participating in the standardisation activity informed by implementation work.
Last updated: 2004-09-30
An implementation of an RDF API and RDF Query implementation, written in Java. Open Source/free software.
Last updated: 2003-11-05. For a feature-rich and well-supported Java RDF API and query language, we recommend the use of HP Lab's Jena2 (tutorial).
A brief summary of work carried out in 2003 to collect and run RDF query test cases with different implementations, including references to chatlogs, resultsets and manifest formats.
Last updated: 2004-03. Work now continues in the W3C's Data Access Working Group.
This report describes the development of a demonstrator for showing the results of searching large scale RDF, presenting the results of the search in contexts of the original sources along with metadata about the transaction using the Redland RDF Application Framework and the Redland Contexts, designed for this purpose.
Last updated: 2004-09-30
The fourth SWAD-Europe developer Workshop on Semantic Web Storage and Retrieval was held 13-14 November 2003 at Vrije Universiteit, Amsterdam, Netherlands and attended by 26 semantic web developers from Europe and the USA discussing practical aspects of developing and deploying semantic web storage and retrieval systems.
Last updated: 2004-01-13
Redland, Raptor and Rasqal - Open Source RDF by Dave Beckett XMLOpen, Cambridge UK, 23 September 2004.
Presentation to W3C RDF Data Access Working Group by Dave Beckett, Leiden, Netherlands, 23 April 2004.