In this paper, an interactive tool for learning the fundamental concepts of communications systems from an information theory point of view is presented. This tool is composed of two parts: a C++ library and a Graphical User Interface application in Matlab. The C++ library is designed following an object-oriented structure and is fully scalable (it is open for future updates). The Matlab-GUI application is a friendly interface that aids undergraduate students to understand the theory. Some of the tool's capabilities are illustrated through classroom examples. In addition, this tool is designed to improve the students' theoretical knowledge of information theory.