[Discuss] What (free software) options are people using for chat?

[greg at freephile.com (Greg Rundlett (freephile))]

It's remarkable that IRC still exists after all these years.  Mostly
because it's free as in freedom.  It has it's limitations to be sure, and
quite a while ago I thought there were things like Jabber/XMPP that would
take over because of the capabilities of the protocols [1] were maturing at
the same time that legal issues were forcing interoperability.

But today there is no single "killer app" for Instant Messaging [2].  (The
same is true for Video Conferencing, but that's another topic.)  By "killer
app" I mean a platform that teams can either join (distributed) or setup
for themselves.  A game-changer and leader, like the Apache HTTPD server.
I do not mean a FLOSS client that can allow you to connect to a proprietary
network.

Slack has been quite popular.  I've never used it, and I'm only interested
in FLOSS platforms. I have no interest in a proprietary platform.

I just learned that the CiviCRM team is using "Mattermost" [3] which has a
compelling story behind it [4] and is for the time being partly open.
Sadly, it could go the way of SugarCRM or countless other 'open source'
companies due to the fact that it's licensed under the Apache license.
Basically, they develop the software where enterprise features are
proprietary and the community edition is abandoned once significant revenue
makes the community version irrelevant to their business.

As an aside, I don't quite understand why they are offering the community
edition under a dual Apache/GNU Affero license. [5]

Will Mattermost become the ground-breaking leader in free chat? What do you
think?  What do you use for team chat?  Are there any FLOSS projects that
are well developed, but not owned? Jitsi [6] was apparently pretty
complete, but is now owned by Atlassian.

[1] https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols
[2] https://prism-break.org/en/categories/gnu-linux/#instant-messaging
[3]
https://civicrm.org/blog/michael-mcandrew/chat-infrastructure-for-civicrm
[4]
http://www.mattermost.org/why-we-made-mattermost-an-open-source-slack-alternative/
[5] https://github.com/mattermost/platform/blob/master/LICENSE.txt
[6] https://jitsi.org/

Greg Rundlett
https://eQuality-Tech.com
https://freephile.org