The W3C Semantic Web Best Practices and Deployment Working Group has published two new working drafts, Representing Classes As Property Values on the Semantic Web and Defining N-ary Relations on the Semantic Web: Use With Individuals. The first "addresses the issue of using classes as property values in OWL. While OWL Full and RDF Schema do not put any restriction on using classes as property values, OWL DL and OWL Lite do not generally allow this use. The only property that can have a class as its value is rdf:type (and its subproperties). The document examines different approaches to representing this ontological pattern in OWL DL and discusses considerations that the users should keep in mind when choosing one of the approaches." The second describes how to handle non-binary relations. "In Semantic Web languages, such as RDF and OWL, a property is a binary relation; that is, it links two individuals or an individual and a value. How do we represent relations among more than two individuals? How do we represent properties of a relation, such as our certainty about it, severity or strength of a relation, relevance of a relation, and so on? The document presents ontology patterns for representing n-ary relations and discusses what users must consider when choosing these patterns." These are expected to become notes, and are not on the recommendation track.
Tim Bray has posted another beta of Genx, his pure C library for outputting canonical XML. This release plugs a memory leak. Haven't we learned by now that programmers should not be managing their own memory? I know there are perfectly good garbage collection libraries for C++. Are there any for plain vanilla C? Genx is published under the expat license. This is a very liberal, non-viral but GPL-compatible license.
In related news, Garrett Rooney has written GenX4r, a Ruby wrapper around Genx.
The W3C CSS working group has updated the working draft of
CSS3
Speech Module.
This spec defines CSS properties used
when documents are read out loud. These include
voice-volume, voice-balance,
speak, pause-before,
pause-after, pause,
cue-before, cue-after,
cue, voice-rate,
voice-family, voice-pitch,
voice-pitch-range, voice-stress,
voice-duration, phonemes,
@phonetic-alphabet. This draft adds new
mark-before, mark-after, and mark properties that attach nnamed markers to the audio stream.