Release engineering deals with all activities in between regular development and delivery of a software product to the end user, i.e., integration, build, test execution, packaging and delivery of software. Although research on this topic goes back for decades, the increasing heterogeneity and variability of software products along with the recent trend to reduce the release cycle to days or even hours starts to question some of the common beliefs and practices of the field. RELENG 2013 is a full-day workshop that aims to provide a highly interactive forum for researchers and practitioners to interact and address the challenges of, find solutions for and share experiences with release engineering, and to build connections between the various communities. The workshop will consist of two keynotes, practitioner talks, paper presentations, working groups and a fishbowl panel for semi-structured group discussions. The two keynotes, presented by John O'Duinn, director of Release Engineering at Mozilla Corporation, and Alan Grosskurth, Release Engineering consultant and ex-Release Engineer at VMWare, Inc., two prominent release engineers in open source and industry, will set the stage for the workshop, introducing the challenges of modern companies related to release engineering. In an effort to engage with practitioners, one of the co-organizers is a release engineer at Mozilla and one third of the PC consists of release engineers, so we guarantee that each paper or abstract submission receives at least one review from a practitioner.