It's a form of Steganography https://en.wikipedia.org/wiki/Steganography

Was referring specifically to the claim about the CIA, I'm aware of steganography.

Vim can absolutely do multiple "frames". They're called splits.

No, it cannot. An Emacs "frame" is a separate editor window, managed by the window manager. Different Emacs frames running the same Emacs session talk to each other--they share the buffer list, etc. Within the Emacs "frame" you can have split "windows".

One Vim session can live only in one window that is managed by the system window manager. You cannot have multiple windows that talk to each other. You can split a single window manager window using ":split" and the like. Vim calls these "windows". You can have multiple tab pages, each of which holding multiple Vim windows, but all these tab pages must reside in a single system window-manager window.

Vim has a help file somewhere saying that Bram Moolenaar knows this is a problem and it's on the todo list.

You can also run Emacs as a daemon, and connect to it from both graphical and tty sessions. So you could ssh into your desktop and (with emacsclient), work with the same instance running on your X desktop.

I did this back in college with XEmacs (90's). I'd leave gnus running at school and open a new frame from home to check mail and news. (You can use this to have two people editing at once too, but you have to avoid avoid opening a minibuffer.)

Although it is not exactly the same, what you can do is start a `screen' session (which can be split with ^a S), and then split your `vi' instances.

A frame in Emacs terminology is actually a top-level window.

So MacVim does have this functionality then, yes? You can have multiple top-level windows, each having multiple tabs, each having multiple splits.

I was curious so i just tested this to see if it did. It does not. Yes you can have multiple tabs and splits, but in emacs each frame shares the same buffer list as well.

They don't share anything. Different buffers, registers, and I think even different extensions loaded.

Concepts will accomplish this when they finally make it into the standard.

Concepts will certainly be nice once they arrive in the standard, but it is already possible today with some trickery. Example checking whether an std::vector<T>'s type is comparable with `operator<`: http://coliru.stacked-crooked.com/a/2ea46e0afd894d3d

The error you get if you try to sort a vector with an unordered type is relatively easy to read:

    main.cpp: In instantiation of 'void merge_sort(std::vector<_RealType>&) [with T = type]':
    main.cpp:45:17:   required from here
    main.cpp:30:5: error: static assertion failed: Element type is not sortable
         static_assert( concept::is_ord<T>(), "Element type is not sortable" );
         ^