What bothers me the most with the current on-premises chat solutions is the lack of a true alternative for jabber/xmpp with OTR (or equivalent e2e encryption) support. I honestly hate that in 2018 there is no way to move away from Pidgin/Adium if you want to keep this functionality.

- RocketChat - OTR breaks very easily, and https://github.com/RocketChat/Rocket.Chat/pull/10094 has been open for months - Matrix / Riot - Last I tried it had the most complex and unusable interface - Mattermost - At first glance seems to include E2E, but when reading a little bit more...not really, just at rest encryption - https://mattermost.atlassian.net/browse/MM-669 - Zulip - nop - https://github.com/zulip/zulip/issues/6096 - Movim - nop - https://github.com/movim/movim/issues/63 ...