Foreword by the Editor [EM Programmer´s Notebook]

In this column, many of our submissions focus on the core computational components of electromagnetic simulation software, the kernel. However, as discussions with any commercial vendor will quickly confirm, much of the effort required to create a really usable electromagnetic simulator goes into the graphical user interface (GUI). This month´s submission discusses software architecture issues, in particular designing overarching architectures for the GUI and kernel. We thank the authors for their interesting contribution.