mattermost

Install command: 
brew install --cask mattermost

Name: Mattermost

Open-source, self-hosted Slack-alternative

https://mattermost.com/

/api/cask/mattermost.json (JSON API)

Cask code on GitHub

Current version: 5.10.2

Requires: macOS >= 10.15

Variations:

Intel sequoia 5.10.2
sonoma 5.10.2
ventura 5.10.2
monterey 5.10.2
big sur 5.10.2
catalina 5.10.2

Analytics:

Installs (30 days)
mattermost 427
Installs (90 days)
mattermost 1,099
Installs (365 days)
mattermost 4,358
Fork me on GitHub