xprop(1) on Linux
The text 434f7c99a6e6, as Debian 7 (Wheezy) shipped it.
property displayer for X
Flags it lists
-
-display -
-font -
-frame -
-fs -
-grammar -
-help -
-id -
-len -
-name -
-notype -
-remove -
-root -
-spy