I have started a page for an implementation of the GangOfFour Observer pattern within Zope: <URL http://www.zope.org/Members/michel/Projects/Interfaces/ObserverAndNotification> Please comment, either here or in the wiki. Tres. -- =========================================================== Tres Seaver tseaver@digicool.com Digital Creations "Zope Dealers" http://www.zope.org