PlugInContainers

Plug-in containers, (aka PICs) are objects which want to support "pluggable" extensibility. Usually, they have some behavior aspect they want users to be able to extend or override by adding one or more PlugIns. For example, LoginManager provides multiple levels and/or methods of authentication by allowing users to "plug in" as many LoginMethods as they need. If a standard LoginMethod is not available, a user can write their own, then plug it into a standard LoginManager without having to change any of LoginManager's code.

The idea is somewhat similar to Java Beans, Active X, and the like, but Zope-specific and oriented towards specific extension needs rather than general component embeddability.