A visual dataflow programming language and environment from the Technical University of Halifax. Prograph is an entirely graphical visual programming language, other than for the text of method names, and supports the program development process in a highly-interactive fashion. Operation icons are connected by data links through which information flows. It supports object orientation via class-based data abstraction with single inheritance. Prograph is available for the Macintosh, and soon for Windows and Unix, from TGS Systems.