This is a very incomplete post (so far) of discord alternatives. In the near future, I'll add rankings and in depth information on each alternative. Stuff may be slightly inaccurate or miscategorized for a little while as I start my research. I will also add links and other info as time goes on.

Discord like

• Stoat (formerly Revolt)
• Mattermost ($$$ Built for enterprise)

Signal Like

• Matrix

Teamspeak Like

• Mumble

Slack Like

• Rocket.Chat

Forum Like

• Discourse

Need to Categorize

• Zulip