Wilbur
Ora Lassila -- contact
About
Wilbur is Nokia Research Center's open source toolkit for RDF (and other Semantic Web formalisms such as DAML+OIL and OWL), written in Common Lisp. Like other RDF toolkits, it offers an API for manipulating RDF data (graphs, nodes, etc.) as well as parsing functionality (parsers not only for RDF, DAML+OIL and OWL but also for XML since one written in Common Lisp did not exist when the Wilbur project was started; it also offers a simple HTTP client API for accessing remote URLs for the same reason). Wilbur also offers a frame system API on top of the RDF data API, including a path-based query language (WilburQL). Wilbur strives for tight integration of RDF data with the intrinsic features of Common Lisp.
Wilbur, as a software system, has its heritage in earlier frame-based knowledge representation systems: BEEF, BONE and PORK, all of which addressed the issue of integrating object-oriented programming with frame-based representation. BEEF and BONE (which pre-dated practical implementations of the Common Lisp Object System) added object-oriented features to a frame system, whereas PORK approached the issue from the opposite direction by taking an object-oriented programming language and adding features of frame-based representation to it; PORK used the Common Lisp metaobject protocol to extend the Common Lisp Object System (CLOS).
Wilbur takes a lower-level approach to integration, by allowing manipulation of RDF graphs. Future development may still address programming issues taking either the “BEEF-approach” (adding programming features to a frame system) or the “PORK-approach” (adding frame features to a programming language). In Wilbur the RDF/CLOS integration focuses on the following areas:
- Ease of use of Common Lisp data structures with RDF - this is achieved via a simple yet flexible query language (WilburQL).
- Input and output of RDF data in a “Common Lisp –friendly” manner - Wilbur takes the read/print consistency rules of Common Lisp very seriously, making it possible to use literal RDF data (nodes and literals) in Common Lisp source files.
- Use of the Common Lisp condition mechanism for signaling unexpected situations – Wilbur’s condition class hierarchy is quite elaborate, allowing precise detection and handling of anomalous situations.
Current Release
1 (stable);
2 (pre-release - check it out and give your comments)
License
This software is licensed under the NOKOS version 1.0a.
Downloads
Related Links
- Wilbur's mainpage at SourceForge
- includes access to releases 1 and 2, Ora's blog, and preliminary API documentation.
- Wilbur-related publications
- listing of Ora's Wilbur, Semantic Web, and RDF related publications.
