the first "large" (~500 loc) program i wrote was a cli chat that worked did this. one program send messages by writing to a NFS file, and the other showed the chat (by continuously reading the file). I spend ages trying to make it one window, by having python's input() not block, but never could.

Got it. Sometimes it feels like I am already doing that as the post compose function gets more and more complex.

Maybe I should add an i-feel-lucky-post button.