Refactoring [Guest editors´ introduction]

Refactoring changes a program´s source code without changing its external behavior, typically to improve the software´s design The articles selected for this issue range from historical, exploring refactoring research´s origins, to practical, exploring software developers´ experiences with refactoring, to theoretical, exploring new refactoring techniques that haven´t yet appeared in the wild. The Web extra at https://youtu.be/f2IK3V9wwa8 is an audio recording of Davide Falessi speaking with guest editors Emerson Murphy-Hill of North Carolina State University, Don Roberts of the University of Evansville, and Peter Sommerlad of Fachhochschule Ostschweiz / Hochschule für Technik Rapperswil about past, present, and future approaches to refactoring.