1. A program output interface to a user from a parallel computer program executing on a parallel processing system, comprising: a display terminal for displaying output on a screen to a user from a parallel program executing on a parallel processing system, said parallel program comprising a plurality of individual tasks executing in parallel with each other, each of said plurality of individual tasks comprising instructions and some of said instructions being graphical element instructions, each particular graphical element instruction specifying a particular graphical element state and a particular graphical element number relative to a particular task in which said particular graphical element instruction appears; a runtime library function in said parallel processing system responsive to execution of any said graphical element instruction for passing a graphical element message to said display terminal, each said graphical element message identifying a particular task in which said graphical element instruction was executed and a particular graphical element number and particular graphical element state specified in said graphical element instruction; and a graphical element display manager for displaying an array of graphical elements on said screen, said graphical element display manager associating each one of said plurality of individual tasks with a unique portion of said graphical elements, said graphical element display manager receiving each said graphical element message and causing a particular graphical element corresponding to a particular task and a particular graphical element number specified by said graphical element message to be displayed at said display terminal in said particular graphical state specified in said graphical element message.