Foreword by the Editor [EM Programmer's Notebook]

After a number of recent columns on accelerating computations, especially using GPGPUs - work which by its nature has to focus on very-low-level machine-specific issues (see, for instance, the December 2010 column) - it is interest ing to again feature a submission considering coding issues at a high level. Whilst much numerical-simulation work is of a one-off nature, for which tools such as MATLAB (which is regularly featured in the column) are ideal, large-scale soft ware brings new issues, not often addressed in our community outside commercial software companies, the software-design strategies of which are often proprietary. In this month's contribution, the author presents ideas from the field of software engineering and object-oriented design, applied to electromagnetic field simulators.