Extending PHP, Zend API

Hello all, I'm currently authoring a book chapter "Extending PHP". It's focus is on extending PHP's function set with custom modules implemented in C etc. Right now I'm trying to figure out Zend's API differences compared to PHP 3's API. I've searched through the discussion archives and available documentation, but couldn't quite figure out the difference between zend_get_parameters_ex() and zend_get_parameters(). Looking at the source I found that zend_get_parameters() does some weird copying of the parameters plus modifying the reference count, but I didn't really understand the intentions there. Also, if anyone has suggestions about what should be contained in the chapter, I'm open for any input. Volunteers for proof-reading are also welcome. I've also heard (and seen in a message in the archives) that a project for creating a reference about Zend's API is underway. Is this still true? Regards, Till