Pixelfed

Pixelfed is open source software for sharing images on a federated social network. It is not one platform: many servers run the Pixelfed software and exchange posts through the ActivityPub protocol, the same protocol Mastodon uses, so you can follow and like accounts that live on another server. The project was started by the Canadian developer known as dansup.

Because Pixelfed is a self-hosted open source project, it is not necessarily European, although several of the largest servers are run in Europe. Choosing a European instance makes it a workable European alternative to centralised photo apps, and running your own server is always an option.