This is a list of all (or all that I know of) single mod or single author/group discord servers in the minecraft mod community. They are listed in order of application (except for the first entry, because Forge). To apply, join the Modded Minecraft discord and use #discord-feedback.
If a widget shows "inaccessible" this just means the server owner does not have the widget enabled, not that the server is down. If you are the server owner, see the footnote.
If your server, or a server you admin, is listed here and the widget displays inaccessible
, you must enable the widget on your server. Go to server settings -> widget and enable it.