In this paper we have presented the design and implementation of the graphical display program for the Thunder and Lightning network protocol simulator. The display application, unlike other Tcl/Tk applications of which we are aware, has the unique requirement that it must be implemented as a separate program running on a machine other than the computer hosting the simulation process. The display and simulator must, therefore, exchange data through the use of sockets. The fact that the display and simulator may be running on dissimilar architectures poses new challenges, despite the portability that Tcl provides. We have used code from the working display application to present the use of XDR in overcoming these inter-platform binary data representation issues. Finally, we have described several areas of Tcl/Tk that could use further development. In particular, we have identified several weaknesses in the canvas widget and described how XDR might be incorporated into Tcl. We believe that the modest effort required to include XDR functionality in Tcl would extend Tcl's socket abstraction beyond that of comparable scripting languages.