My name is David Sheets. I will be a sophomore at MIT this fall. I like to be at the intersection of theory and practice.
The new parser is not as portable as the old parser at this time. It has only been tested in Firefox 1.5 but should work in any browser that supports the DOM Level 2 specification.
RDFParser runs at a speed similar to Jim Ley's parser. One can easily construct example RDF/XML files that run faster on one parser or another. I took five files that the tabulator might come across in day-to-day use and I ran head-to-head benchmarks between the two parsers.
Parse time is highly influenced by compact serialization. The more nested the RDF/XML serialization, the more scope frames must be created to track features from the specification. The less nested, the fewer steps to traverse the DOM, the more triples per DOM element.
Planned in the next release of RDFParser is a callback/continuation system so that the parser can yield in the middle of a parse run and allow other important page features to run.
API documentation for RDFParser included in the Tabulator 0.7 release is available.
Finally, I'd be happy to hear from you if you have questions, comments, or ideas regarding the RDFParser or related technologies.