xprop(1x) on Linux
The text 4675aebb22d1, as Debian 3.0 (Woody) shipped it.
property displayer for X
Flags it lists
-
-display -
-font -
-frame -
-fs -
-grammar -
-help -
-id -
-len -
-name -
-notype -
-remove -
-root -
-spy