Visual programming languages have facilitated the application development process, improving our ability to express programs, as well as our ability to view, edit and interact with them. Yet even in programming environments, productivity is restricted by the primary input sources: the mouse and the keyboard. As an alternative, we investigate a program development interface which responds to the most natural human communication technologies: voice, handwriting and gesture. Speech- and pen-based systems have yet to find broad acceptance in everyday life because they are insufficiently advantageous to overcome problems with reliability. However, we believe that a visual programming environment with a multimodal user interface properly constrained so as not to exceed the limits of the current technology has the potential to increase programming productivity for not only those people who are manually or visually impaired, but for the general population as well. In this paper we report on such a system.