This is X11.app's fault, not Dockless, but I found out the hard way that the new X11.app does not behave well when Dockless tries to make it dockless. For example, launchd launching no longer works.

I had used this previously to run the X11 server in the background, which I started on login on 10.4 and earlier.

X11 now "just works" whenever an X-windows program is launched. But the icon in the dock can be a bit irritating.