[petercammeraat]

Are there more governments and/or organisations that have their own Mastodon instance?

[M2Ys4U]

The EU has one (social.network.europa.eu), as well as a PeerTube instance (tube.network.europa.eu).

Germany has social.bund.de as well as a couple of public service broadcasters (like ZDF who run zdf.social).

[eythian]

Gemeente Amsterdam has one: https://social.amsterdam.nl/public/local