gnuchessx(6) on Linux
The text 233d9d7a1a90, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy) shipped it. The page shows this text now.
Plays a game of chess, either against the user or against itself.