SPIN - Frequently Asked Questions

Question: Are there any plans to let the W3C review SPIN as a standard?

Answer: Yes, SPIN has been published by W3C as a Member Submission supported by TopQuadrant, Rensselaer Polytechnic Institute and OpenLink Software. The W3C has responded that it may review SPIN in conjunction with the RIF standard.

Question: How does SPIN compare to SWRL?

Answer: SWRL has been around for a couple of years now, and therefore has some tool support and coverage in conference papers etc. Like SPIN, SWRL has an RDF syntax to represent rules. However, we believe that SPIN is superior to SWRL in almost every respect, mainly because SPIN is based on SPARQL. SPARQL is well established and supported by numerous engines and databases. This means that SPIN rules can be directly executed on the databases and no intermediate engines with communication overhead need to be introduced. Also, SPIN is more expressive than SWRL, because SPARQL has various features such as UNIONs and FILTER expressions. SPIN has an object-oriented model that arguably leads to better maintainable models than SWRL's flat rule lists. Finally, SPIN goes far beyond being just a rule language, and also provides means to express constraints and to define new functions and templates.

Question: My colleagues and I think that SPIN has some great features. However, we are curious if there is any project out there to create an open source library to utilize the language. While we are happy TBC users, and our client does have a TBL server, our models need to be able to be utilized by applications that don't utilize COTS components like TopBraid.

Answer: There is an open source library called TopBraid SPIN API which is already in routine use in several projects. This API has intentionally been designed to be independent from any other TopBraid-related dependencies, so that it can be used in any conceivable Java application including servlets. It just depends on Jena.