I am working on a PR for 2nd level caching for zcatalog by means of plone.memoize in order to improve the catalog search of big Plone-Sites. The GPL licensing of plone.memoize conflicts the ZPL license of Products.ZCatalog, therefore plone.memoize cannot be generally used for the enhancement. In my opinion it would be a waste of resources if the very useful cache features of plone.memoize could not be used in other Zope projects. Is it possible that plone.memoize is re-licensed for ZPL compatibility?