M. Wimmer: Software Evolution in Time and Space: Unifying Version and Variability Management, Dagstuhl Seminar 19191, May 5 – 10 , 2019, co-organized with Manuel Wimmer (JKU Linz, AT), Thorsten Berger (Chalmers and University of Gothenburg, SE), Marsha Chechik (University of Toronto, CA), Timo Kehrer (HU Berlin, DE), Schloss Dagstuhl, Germany see dagstuhl, http://dx.doi.org/10.4230/DagRep.9.5.1

Modern software systems evolve rapidly and often need to exist in many variants. Consider the Linux kernel with its uncountable number of variants. Each variant addresses different requirements, such as runtime environments ranging from Android phones to large super-computers and server farms. At the same time, the Linux kernel frequently boasts new versions, managed by thousands of developers. Yet, software versions – resulting from evolution in time – and variants – resulting from evolution in space – are managed radically differently. Version management relies on a version control system (Git) and sophisticated workflows – concepts that have been developed for decades in the field of software configuration management (SCM).