Tried that once, opened the file in vi, blinked, and somehow mailed it to my dentist. Highlighter never did that.

Success! Coffee through nose achieved.

Printouts, usually many of them, are the original "overlapping windows".

Exactly. I used to stack printouts on the floor in layers. Top one was active, bottom one was swap. If you walked too fast past my cube, you'd trigger a context switch.