pmmessage(1) on Linux
The text 6f1da092fef6, as Debian 8 (Jessie), Debian 6.0 (Squeeze) shipped it.
general purpose dialog box
Flags it lists
-
-B -
-b -
-buttons -
-c -
-center -
-default -
-exclusive -
-file -
-font -
-geometry -
-header -
-icon -
-nearmouse -
-noframe -
-noprint -
-noslider -
-print -
-t -
-timeout -
-useslider