Graphical User Interfaces (GUIs) are being increasingly used in the classroom to provide users of computer simulations with a friendly and visual approach to specifying all input parameters and increased configuration flexibility. In this paper, the authors first describe a number of software and language options that are available to build GUIs. Subsequently, a comprehensive comparative assessment of possible alternatives is undertaken in the light of a benchmark educational program used in a course on Computational Fluid Dynamics (CFD) at the University of Michigan. For the GUIs presented, their educational value with respect to flexible data entry and post-processing of results has been demonstrated. In addition, the authors offer recommendations for pros and cons of available options in terms of platform independence, ease of programming, facilitation of interaction with students and flexibility.