The last few years have witnessed a significant increase in the frequency and magnitude of involving third-party application developers in software platforms. While this involvement offers great opportunities in building and sustaining platform innovation, it also exposes platform owners to significant challenges. Typically, platform owners facilitate the involvement of third-party developers by providing resources, referred to in this thesis as boundary resources, that give access to the platform, shift design capability, and facilitate the use of the platform’s core technologies. At the same time, these resources have the potential to be used to maintain platform control. This involves seemingly conflicting goals that creates a challenge for platform owners in finding the right balance.

The main objective of this thesis is to investigate and understand the role of boundary resources in platform owners’ efforts to stimulate third-party development. To this end, this thesis proposes a theoretical model of boundary resources. This model centres on various drivers behind boundary resources design and use, and how these drivers interact in third-party development. The thesis also presents a comprehensive view of governance and strategizing practices used by platform owners through boundary resources. This thesis comprises a cover and a collection of five published research papers. The thesis applies a qualitative research method and employs multiple case studies. Boundary resources, innovation networks and platform governance perspectives have been synthesized to build a theoretical  basis to analyze the empirical findings.

This thesis complements and extends the literature on software platforms, and the insights derived from the thesis enhance previous research on third-party development. In addition, it provides a focused theoretical account of the interfaces between platform owners and third-party developers that contributes to the body of knowledge developed around using tools for innovation.