The packages usually missing are at least: libx11-dev libxt-dev libxext-dev
--- Begin Message ---I'm not familiar enough with Linux and APT to figure this one out: what are the prerequisites for 9vx that are not intrinsically met by a standard UBUNTU installation? The immediate need is related in some way to x11-draw, but that is not the name of an apt package.++L
--- End Message ---
