2015 marks an anniversary for the software aging and rejuvenation (SAR) community: The seminal paper "Software rejuvenation: Analysis, module and applications" by Huang, Kintala, Kolettis and Fulton, which started research on the software aging phenomenon and the possibility of counteracting it via software rejuvenation, appeared exactly 20 years ago. For the last seven years, WoSAR has been the international event bringing together researchers and practitioners involved with the theoretical and experimental aspects of software aging and rejuvenation. As a satellite event of the premier symposium, ISSRE 2015, WoSAR 2015 aims to provide a forum for researchers and practitioners to present and discuss the state of the art and the new challenges in software aging and rejuvenation research, as well as a unique opportunity for establishing collaborations among several research groups interested in this research field.