vimdiff(1) on Linux
The text 05f5a5d7a8fb, as Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze) shipped it.
edit two, three or four versions of a file with Vim and show differences