Diffpack is a collection of the C++ libraries used to numerically solve the partial differential equations PDEs, using the object oriented programming in the C++. The Diffpack version for the Unix/Linux platforms, has so far primarily been a collection of the simulators run from the command prompt only, unlike the Windows version where a fully interactive graphical user interface (GUI} has existed for a while. There have been some attempts to change this and several smaller GUIs, like gui.pl (for adjusting the simulation parameters and running the simulation), simresgui (for exporting the simulation results to different visualization formats) and vtkviz (for visualizing the simulation results in VTK), have been programmed, although none of these have been functioning as a unified application with GUI.The aforementioned smaller GUIs (gui.pl, simresgui, vtkviz), bypass the command prompt and offer the user a slightly more intuitive option of a window based interaction with a simulator. These GUIs cover all of the aforementioned processes in the execution chain, but their main problem is their lack of interaction with each other, as well as being rather "old fashioned". Some of them are also offering only a few options to the user.The main purpose of this thesis is therefore to make a GUI applicationwhich would combine all these processes into one unit, and enable theuser to bypass the prompt line.