Since version 22.12 the JGoodies Showcase demonstrates responsive layouts in Content > Forms.
Blog
Runtime Error Dialogs
The JGoodies Showcase now demonstrates two examples for dialogs that show a runtime error, see Dialogs>Messages>Errors. You can show and hide a problem report with stack trace, and you can send a problem report, or copy the report to the system clipboard resp.
Showcase 2.0b8
An object search example for articles has been added to Basics>Completion>Object.