Really, extending the todo.txt todo-list format (http://todotxt.org) to being a blog platform is as simple as having a heredoc style delimiter for each post. Then of course, you're just recreatin org-mode from first principles.
Social media is also merely the exchange of plain text and media files.
If only we had a simple and free platform that had the following features:
* Supports multiple simultaneous users
* Has simple user and group access control
* Treats everything as a sharable file
* Easy for admins to securely deploy out of the box
* Easy for users to securely connect out of the box
* Uses few enough resources that it can be ran on effectively any computer, no matter how powerful.
If only we had such a mythical system, we could decentralize the net. If.
I don't understand all those features you're asking for, but maybe some adaptation of https://fossil-scm.org ? It's a wiki, blog, DVCS, and bug tracker all in one program, using sqlite as a backing store. An instance of it runs in about around 2MB of memory on a small vps.
That's an old video promoting Unix, so I don't see what you're getting at. Unix is not a distributed OS. The web has to work over communications channels with fairly high latency, so you don't want a file-system-like interface either. If you have something specific in mind, maybe you could say what it is instead of being coy.
Social media is also merely the exchange of plain text and media files.
If only we had a simple and free platform that had the following features:
If only we had such a mythical system, we could decentralize the net. If.