Saxon

We are using a PE OEM license, and we have installed the saxon-license.lic file in the tomcat application classpath and run the supplied activate() method on the Saxon implementation of the TransformerFactory. This all works just fine, but I am not clear on exactly what is going on here and I can't find an explanation for the proper method of applying the activate license process in the documentation. When do we need to run the activate() method? Do we need to store the license file in the app after activation, or is it just needed initally? Right now we do it on the first instantiation on any call to the web server for a transform. Is this something that can be stored as a singleton when the app server starts up?

Any help or a link to documentation that explains how this is supposed to be done would be appreciated.