jugmac00 via Plone Community wrote at 2019-9-23 06:45 +0000:
Can anybody explain me where both the zope.app.* and the z3c.* name spaces originated from? I have a feeling that those are related to Zope 3?
"zope.app" has been the application layer of the Zope 3 web application
framework. "z3c" designates a community developing components
based on the Zope component architecture (which was identified for
some time with Zope 3; later Zope 3 was (mentally) split into
an application framework and general infrastructure (called Zope toolkit)).
Are packages from these name spaces compatible with current Zope 2/4/5?
As far as I know, the Zope 3 web application framework is no longer
maintained. Some packages may have been made compatible with new Zope
versions - because they are still actively used - but others likely have not.
The same likely applies as well to "z3c" packages: important ones
have been made compatible (e.g. "z3c.form") but there might still
be some parts not yet updated.