php rdf apis

Hi there,

I'd like to start a thread to discuss about available RDF APIs for PHP.

I took a look at Benjamin Nowack's ARC2 (http://arc.semsol.org). It looks sound and it's already used in several projects. It features several i/o parsers/serializers, an integrated RDF store, SPARQL query engine (didn't read anything about compliance with W3C DAWG test cases...), SPARQL endpoint, some simple inferencing and there are also some plugins I didn't look at for now.