GMail-like user labels in IMAP/dovecot, situation in 2017?

Hello,

I am in the process of updating my IMAP dovecot installation and I was wondering what is the current state of the art for GMail-like user-defined labels.

Are GMail-like user-defined labels now somehow achievable with dovecot?

If now, what is missing? Standardized metadata formats? Support in clients?

I searched the web a bit but I could not find any activity in the relevant IETF working groups. That seems strange to me, because the user-defined labels looks like a feature many users would like to have. I suppose I haven't found the relevant discussion group. Is this kind of enhancement to IMAP being discussed somewhere?

Regards,

-- Gioele Barabucci gioele@svario.it