Mattermost is an open source, private cloud Slack-alternative.
We're "Slack-compatible, not Slack limited" and you'll find all the core features of Slack plus many benefits added by the open source community--like markdown support, translation into 11 languages, multi-team accounts, searchable hashtags and much more: https://www.mattermost.org/what-slack-might-learn-from-its-o...
Mattermost had threaded messaging since 2015, it used to be called "Replies" and we renamed it "Threaded messages" in April 2016: https://about.mattermost.com/mattermost-3-4-7/
If anyone wants to try it out, you can join https://demo.mattermost.com/
Mattermost is an open source, private cloud Slack-alternative.
We're "Slack-compatible, not Slack limited" and you'll find all the core features of Slack plus many benefits added by the open source community--like markdown support, translation into 11 languages, multi-team accounts, searchable hashtags and much more: https://www.mattermost.org/what-slack-might-learn-from-its-o...