Quick update: https://holos.social is now up and running!
Source code will be public very soon (link shows 404, repo still private). Registrations will follow shortly after.
Site available in English and French only for now.
For self-hosters, you'll have three options: an all-in-one install script (auto-detects OS, configures everything), Docker, or full step-by-step manual setup. All options are fully documented.
If you have a fediverse account, you can quote this note from your own instance. Search https://mastodon.social/ap/users/115588590742214453/statuses/115611686020244401 on your instance and quote it. (Note that quoting is not supported in Mastodon.)