The concept of visual programming languages is described and some necessary terms are defined. The value of visual languages is presented and a number of different visual languages are described. Various issues, such as user interface design, are discussed. As an example of a visual programming language, a graphical data flow programming environment is developed for the Macintosh workstation which functions as a preprocessor to a data flow simulator developed at RIT. Examples are presented demonstrating the use of the language environment. Issues related to the development of the programming environment are described and conclusions regarding the development of visual programming languages in general are presented
