In CMF, a “skin layer” is defined as a collection of templates and code (Python scripts, DTML methods, etc) that can be activated and deactivated within a particular setup. A collection of active “skin layers” grouped in a particular order forms a “skin”. “Add-on” CMF products often provide skin layers that are activated within a particular skin to provide the site with additional features.
To override static resources using a “search path” much like a set of skin layers, Pyramid provides the concept of resource overrides. See Overriding Resources for more information about resource overrides.
While there is no analogue to a skin layer search path for locating Python code (as opposed to resources), view code combined with differing predicate arguments can provide a good deal of the same sort of behavior.