Small code sample and should new code be aiming for PEAR2? PHP6?

Hi, Thanks to everyone who has answered my questions so far. You all have been very helpful. I wanted to post a link to the very beginnings of a package I've started to code for RDF graphs. http://www.stephenbach.net/rdf/ At this point, I'd certainly love any and all feedback, but please keep a couple things in mind. This is very rough and I'm looking for feedback mostly on issues of general API design, *especially* the common interface for RDF graphs. While I'm also eager to hear what others have to say about more specific details, remember I still have a lot of work planned for myself on those details. Also, before I go any further with coding, I want to touch base with the PEAR developers and see if I'm on the right track. I don't have a lot of information about PEAR2 or PHP6. As someone who's working on a new package in the hopes of it being accepted into PEAR, for what versions of PEAR and PHP should I be coding? The code I have now is geared towards PEAR2, but thats based solely on the now somewhat infamous PEAR2 standards RFC. As for PHP6, do any developers have any info/advice? Should I try to develop my code based on source snapshots of PHP6? Wait? Code for PHP5? Thank you all for any feedback you can provide.