Sandstorm

Sandstorm is a self-hostable web productivity suite, implemented as a security-hardened web app package manager. You install apps to create documents, spreadsheets, blogs, git repos, task lists and more, in much the same way you would install apps on a phone. It is open source and can be installed on any x86-64 Linux system.

Each document, chat room, mailbox, notebook or blog you create is a "grain". Sandstorm containerizes every grain in its own sandbox, from which it cannot talk to the outside world without express permission, and grains stay private until you share them. A unified access control system covers data from every app, so you can see who has access and revoke it.

Apps come from an App Market and update automatically. Examples named on the project site are Etherpad for documents, Davros for file storage, Wekan for task and project management and Rocket.Chat for chat. A developer hub in the documentation explains how to package apps for Sandstorm.

The project is built by a community of volunteers. The older sandstorm.io site states that it is historical, from when Sandstorm was a startup, and that the open source project has moved to sandstorm.org.