I love this video about 'ed', the standard Unix text editor. I'll admit that in nearly 30 years of using Unix, my occasional interactions with ed have involved opening it accidentally and immediately exiting with ctrl-c. Having used vi and vim for most of that time, it's interesting to see how much of vim's interface draws from ed.

Is MS-DOS `edlin` related in any way to `ed`?

Wikipedia:

“Edlin was created by Tim Paterson in two weeks in 1980, for Seattle Computer Products's 86-DOS (QDOS) based on the CP/M context editor ED, itself distantly inspired by the DEC PDP-10 TOPS-10 EDIT text editor.”