Mattermore: Mattermost, but More
A patched build of Mattermost that turns paywalled features back on for self-hosters: group calls, recording, local transcription, single sign-on and guest accounts.
Mattermost is a good self-hostable team chat, but several things you would expect on your own server sit behind a paid licence. Mattermore is my attempt to switch those back on.
It turns on group audio calls in any channel, call recording, transcription on your own hardware, single sign-on with any OIDC provider, guest accounts, no user limit and full message history. Group video calls are not in the current release yet, and are being ported.
It is not a classic fork with merges. The upstream release tags are pinned, and a series of patches for the server, the Calls plugin and the transcriber is applied to a clean checkout of those tags. When Mattermost releases a new version, I rebase the patches instead of resolving merge conflicts. A workflow opens an issue when a new upstream release appears, and pushing a tag builds the container image.
The code is AGPL-3.0, like the upstream it builds on. The site at mattermore.dev has the docs and an install guide. For people who would rather not run it themselves there is a hosting request form, and requests arrive as tickets in Balie.
It is live and maintained actively.