Mattermost
Open Slack clone
What matter most comes from
Slack has strict age restrictions in its terms of use, and cannot be used by unexplored junior high school students, so we host and operate Mattermost on our own. ---
This page is auto-translated from /nishio/Mattermost using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.