What about CustomDrawn-X11 then? At least according to the wiki it's supposed to be working in principle.
Ok, I didn't remember that one. The CustomDrawn widgetset does not work very well. I was not able to run any application with it last time I checked.
Aside from a
compile error the X11 backend does work, though quite some components are not yet implemented (e.g. TCustomListBox or menus).