[rules-users] which libraries to use api or core

Hi drools-developers, I'd like to integrate drools in my application. I read in some threads that the structure of the libs has been changed in the newest version, so that same classes exist in several jars. So, if I am to use a class from the old one (core), is it safe enough for my appl? I mean will it run later when the libraries are completely separated? Or would it be preferable to use directly the new ones (from drools-api)? Thanks for advise BB