ISWC and OWL 1.1
I have spent last week at the International Semantic Web Conference (ISWC) and then the OWL 1.1 workshop in Athens, GA. At ISWC, we presented our TopBraid product line at a booth, and I was busy with demos instead of attending talks. I received overwhelmingly positive feedback on TopBraid Composer, and people regard it as a significant move forward compared to Protege. During my time at Stanford I did not hear so many complaints, and I guess this is because people seldom care to voice their criticism - users who are unhappy with a tool simply disappear and move elsewhere. This probably also explains why I have a hard time getting any negative responses about Composer these days. So please - if you have ever tried TopBraid Composer, don't forget to tell me about what you dislike about it!
The OWL 1.1 workshop was very interesting and encouraging, because there is a lot of energy behind the next steps for an OWL 1.1 standard. This standard will include some features that many users need, for example the ability to express numeric value ranges (e.g., age > 18). The schedule to finish 1.1 is tight, and we at TopQuadrant will do what we can to support this movement. In particular, TopBraid Composer will soon have support for several 1.1 features, and come with a corresponding version of the Pellet reasoner.
My main issue of concern is that the OWL 1.1 working group could hit a road block due to its tendency to move OWL away from its RDF foundation. While there will be an RDF exchange syntax, the focus of the specifications lies in an abstract syntax (supported by an XML schema and UML diagrams). This design puts the position of OWL in the Semantic Web stack into question and will very likely lead to resistance. Let's hope that a suitable compromise is found to satisfy each view point and not to delay the 1.1 process because of (philosophical?) battles among the "Semantic" camp and the "Web" camp.
Based on my background as a tool developer, my personal input into this discussion is that almost all semantic web applications and APIs are based on RDF triples, and that introducing another XML syntax for OWL could unnecessarily fragment this community and make it more difficult to link models on the web. While I agree that the layering of OWL on RDF has some drawbacks, the layering also means that a lot of RDF infrastructure is directly accessible to OWL tools. In my experience both at Stanford and here with TopQuadrant, the benefits of having an RDF foundation clearly outbalance any disadvantages.