This information can be obtained with the -queryExtensions option. Use of this option on servers that dynamically load extensions will likely cause all possible extensions to be loaded, which can be slow and can consume significant server resources. Detailed information about a particular extension is displayed with the -ext extensionName option. If extensionName is all, information about all extensions supported by both xdpyinfo and the server is displayed. Xwininfo Xwininfo is a utility for displaying information about windows.
Various information is displayed depending on which options are selected.
If you do not choose an option, -stats is assumed. Alternately, the -name option may be used to specify which window is desired by name. There is also a special -root option to quickly obtain information on the screen's root window. You can use this tool to diagnose, debug, and verify colormaps and their contents in applications that use multiple colormaps and visuals. Cmapdoctor You can download cmapdoctor from the Developer Toolbox.