%0 Journal Article %J Information and Software Technology %D 2011 %T A comparative study of challenges in integrating Open Source Software and Inner Source Software %A Stol, Klaas-Jan %A Ali Babar, Muhammad %A Avgeriou, Paris %A Fitzgerald, Brian %K Open Source Software; Inner Source; Software development; Challenges; Case study; Empirical studies %X Context Several large software-developing organizations have adopted Open Source Software development (OSSD) practices to develop in-house components that are subsequently integrated into products. This phenomenon is also known as “Inner Source”. While there have been several reports of successful cases of this phenomenon, little is known about the challenges that practitioners face when integrating software that is developed in such a setting. Objective The objective of this study was to shed light on challenges related to building products with components that have been developed within an Inner Source development environment. Method Following an initial systematic literature review to generate seed category data constructs, we performed an in-depth exploratory case study in an organization that has a significant track record in the implementation of Inner Source. Data was gathered through semi-structured interviews with participants from a range of divisions across the organization. Interviews were transcribed and analyzed using qualitative data analysis techniques. Results We have identified a number of challenges and approaches to address them, and compared the findings to challenges related to development with OSS products reported in the literature. We found that many challenges identified in the case study could be mapped to challenges related to integration of OSS. Conclusion The results provide important insights into common challenges of developing with OSS and Inner Source and may help organizations to understand how to improve their software development practices by adopting certain OSSD practices. The findings also identify the areas that need further research. Highlights ► We performed a case study that has adopted Open Source development practices. ► We studied the challenges encountered and approaches taken by the organization. ► We performed a systematic review to identify challenges related to Open Source. ► We compared the findings from the review to the findings from the case study. ► Most identified challenges could be mapped to the findings from the literature. %B Information and Software Technology %V 53 %P 1319 - 1336 %8 12/2011 %U http://www.sciencedirect.com/science/article/pii/S095058491100142X %N 12 %! Information and Software Technology %R 10.1016/j.infsof.2011.06.007