A></H2>
One example of user-defined node shapes is provided by Mark Rison of CSR.
These are the <A  HREF=http://www.sdl-forum.org/SDL/index.htm>SDL</A> shapes.
These are available as PostScript functions whose use is described in
<A HREF="http://www.graphviz.org/Documentation/html/shapehowto.html#psprocs"> External PostScript procedures</A>.
The necessary PostScript library file and sample use can be found in the
<tt>contrib/sdlshapes</tt> directory in the release. Please note the
COPYRIGHT AND PERMISSION N