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.