Zope can run in debug mode, which enables some debugging and developer-friendly behavior:
- dtml methods, page templates, pythonscripts, external methods (what else ? everything ?) are reloaded from the filesystem on each view ?
- logging works differently (more of it ? in the foreground ?)
- errors are displayed with more verbose tracebacks ?
- ...
The details may vary slightly between Zope versions.
Zope runs quite a bit slower (how much ?) in debug mode, so it's not recommended for production sites. NB with Zope version 2.7 and older, debug mode is on by default. (!)
It's controlled by the debug-mode option in zope.conf. With Zope 2.6 and older, use the -D flag at startup.