The main features of IELU’s GUI are shown. a Two interactive 3D visualizations, in the MRI space with a glass cortical surface, and in the CT space with no surface. Implanted depth electrodes are also shown. b At the bottom of the GUI, the user can manage the current data, interact with the visualization, alter node assignments and configure program settings settings. c A python shell is also provided, exposing the program’s internals for short scripting. d The local electrode geometry can be adjusted in a separate window. e IELU has many configuration options available