We have this Slack chat service for Gretl and related subjects (also
non-related ;) )
It is another channel that anyone can use for rapid exchange of files and
discussions, and even face-to-face calls, or meetings.
This is the invite link:
This is the URL: https://gretl-econometrics.slack.com
Note: The service is free, so the conversations and files would not be
permanent. Important conversations should be copied to this mailing list.