To me the main 2 primitives that make Emacs the extensible crossplatform app/platform/os/whatever you want to call it are these: * everything is a buffer, whic

To me the main 2 primitives that make Emacs the extensible crossplatform app/platform/os/whatever you want to call it are these: * everything is a buffer, which in essence is a grid of text, that's the UI primitive, if you can render a grid of text you can probably build an emacs UI easily. * every action/command is an elisp function that operates on these buffers Combine these two and you can create pretty much anything. Code written in elisp that outputs buffers. An analogy with the modern web as a platform: elisp is the JavaScript and buffers are the DOM.