To cope with complexity, modern software-intensive systems are often split in different concerns, which serve diverse stakeholder groups and thus must address a variety of stakeholder concerns. These different concerns are often associated with specialized description languages and technologies, which are based on concern-specific problems and solution concepts. Software developers are thus faced with the challenging task of integrating the different languages and associated technologies used to produce software artifacts in the different concern spaces. Part of the series, GEMOC 2014 is a full-day workshop that will bring together researchers and practitioners in the modeling languages community to discuss the challenges associated with integrating multiple, heterogeneous modeling languages. The languages of interest range from requirements to runtime languages, and include both general-purpose and domain-specific languages. Challenges related to engineering composable languages, well-formed semantic composition of languages and to reasoning about systems described using heterogeneous languages are of particular interest. GEMOC 2014 will provide an open forum for sharing experiences, problems and solutions on the conjoint use of multiple modeling languages. This workshop will be the place where concrete artifacts, ideas and opinions are exchanged in order to reap constructive feedback. Following the first edition last year, a major objective of this 2014 edition is to continue collaborations and to expand a community that is focused on solving the problems arising from the globalization of modeling languages.