\setupoutput[pdftex]
\setupcolors[state=start]

\startuseMPgraphic{FunnyFrame}
picture p ;
numeric o ;
path a,b ;
pair c ;

p:= textext.rt(\MPstring{FunnyFrame}) ;
o:= BodyFontSize ;
a:= unitsquare xyscaled(OverlayWidth,OverlayHeight) ;
p:= p shifted(2o,OverlayHeight-ypart center p) ;

drawoptions(withpen pencircle scaled 1pt withcolor .625red) ;
b:= a superellipsed .95 ;
fill b withcolor .85white ;
draw b ;
b:= (boundingbox p) superellipsed .95 ;
fill b withcolor .85white ;
draw b ;
draw p withcolor black ;
setbounds currentpicture to a ;
\stopuseMPgraphic


\defineoverlay[FunnyFrame]
  [\useMPgraphic{FunnyFrame}]

\defineframedtext[FunnyText]
  [frame=off,
   background=FunnyFrame]

\def\StartFrame{\startFunnyText}
\def\StopFrame{\stopFunnyText}
\def\FrameTitle#1%
{\setMPtext{FunnyFrame}{\hbox spread1em{\hss\strut#1\hss}}}

\setMPtext{FunnyFrame}{}%initializethetextvariable


\starttext

\FrameTitle{Test}
\StartFrame

\input zapf\relax

\StopFrame


\stoptext