Task

Create a simple X11 application,   using an X11 protocol library such as Xlib or XCB,   that draws a box and   "Hello World"   in a window.

Implementations of this task should   avoid using a toolkit   as much as possible.




Needs["GUIKit`"]
 ref = GUIRun[Widget["Panel", {
    Widget[
     "ImageLabel", {"data" -> 
       Script[ExportString[Graphics[Rectangle[{0, 0}, {1, 1}]], 
         "GIF"]]}],
    Widget["Label", { "text" -> "Hello World!"}]}
   ]]