Xrestop uses the X-Resource extension to provide ‘top’ like statistics of each connected X11 client’s server side resource usage. It is intended as a developer tool to aid more efficient server resource usage and debug server side leakage.

It should work with any server supporting the “X-Response” extension, including the xorg server and XFree86 4.3+. Run the following command to see if your server supports this extension:

xdpyinfo | grep Resource

For more information see the Xrestop page on freedesktop.org.