OpenModelica is an open-source based development environment for Modelica, and an open source modelling and simulation platform. One of the main reasons for this thesis is the desire to change the existing plotting package into something more future safe due to performance issues of the existing plotting package in the OpenModelica framework. The package should be used in all OpenModelica tools, OMEdit, OMShell, and OMNotebook. The second part of the thesis includes implementing two additional shapes, a text shape and a bitmap shape to OpenModelicas graphical editor OMEdit. As a result of this work, a new plotting tool was developed and adopted as part of the OpenModelica platform; OMPlot.