Hi all I've been working on porting the Dynatree (a dynamic tree-like) widget to z3c.form: https://github.com/collective/collective.dynatree My (temporary) fork is here: https://github.com/syslabcom/collective.dynatree And for this I needed a hierarchical tree-like vocabulary. So I've created a TreeVocabulary in zope/schema/vocabulary.py, based upon the existing SimpleVocabulary. Instead of fromValues or fromItems, it has fromDict, to construct the vocab from a dict. And the internal representation, self._terms, is a dictionary. My branch is here: http://svn.zope.org/zope.schema/branches/jcbrand-treevocabulary/ The only changes are the new TreeVocabulary in zope/schema/vocabulary.py and the tests for it in zope/schema/tests/test_vocabulary.py Can someone please take a look and give some feedback? Thanks J-C