Kinto : Kinto is a lightweight JSON storage service with synchronisation and sharing abilities.
CryptPad : CryptPad is the Zero Knowledge realtime collaborative editor.
Encryption carried out in your web browser protects the data from the server, the cloud ...
Garage : An open-source distributed storage service you can self-host to fullfill many needs.
Gitea : Gitea is a community managed fork of Gogs, lightweight code hosting solution written in Go and published under the MIT license.
Cachet : Beautiful & simple service statuses. The open source status page system, for everyone.
droppy is a self-hosted file storage server with a web interface and capabilites to edit files and view media directly in the browser. It is particularly well-suited to be run on low-end hardware like the Raspberry Pi.