OWL api

Hello,
I have to write out an OWL file from a PHP application so I need some
OWL APIs that allow me, for example, to create a new class, to set
restriction on this class, to create a new property, a new individual
and so on; I don't need to read the owl file nor to perform reasoning
on the ontology created; are there any PHP class or application
suitable for me?
I saw RAP (http://sites.wiwiss.fu-berlin.de/suhl/bizer/rdfapi/) but It
seems to me from the documentation that not all the owl features have
been implemented.

Thanks.

Regards,

Eugenio.