This paper will present a prototype open source CAD system developed recently by a join effort among Harvard, CMU, and MIT. The system is composed of an expandable user interface, a data structure that supports 2D and 3D objects, image processing capabilities, animation, network communication (TCP/IP), serial interface, and file processing modules that can be expanded. The idea was to develop seed modules that can interact with one another in order to be modified, expanded, or new ones added. The language used is Processing and the setup is made to be implemented in an open source format (i.e. GNU and Google Code). The system is an open source universal architectural CAD system that will hopefully serve as the software standard for education and practice.