background-pixmap, border-pixmap can also be 'none or a symbol

set-gcontext-clip-rectangles! not implemented

Need a general keyword wrapper for
  1) functions like create-window that receive a vector
  2) functions with many arguments in general

High-level interface for wm-hints/size-hints not implemented

x-io-errors should not be handled in Scheme (client must exit
after fatal error)

P_Copy_Area, P_Copy_Plane:  initialization of dpy is broken

P_Get_Property:  replace Make_Integer by Make_Unsigned?  Where else?

font-name can return a symbol as well as a string

extents-attributes, max-char-attributes, and min-char-attributes
are bogus and should be removed

there is currently no support for different screens and visuals