I've working on Colanode, an open-source & local-first Slack and Notion alternative that you can self host. You can use Colanode for real-time chat, as a knowledge center, project management or file storage. As a local-first application, Colanode offers full offline support, allowing you to work even when you’re not connected to the internet or the server is not available. You can host it in any environment (with minimal dependencies), giving you full ownership and control over your data.