The emergence of open source software (OSS) as a form of peer production and innovation challenges theories of organisation and strategy due to its non-reliance on traditional governance mechanisms to organise production. OSS requires firms to rethink the processes that facilitate value creation and capture. The objective of this paper is to theorise how firms create and capture value from OSS. We derive a model from extant research and refine it through the study of three inter-organisational networks. The findings reveal how a firm's ability to access a value network of complementors is crucial for effective value creation and capture. Two types of networks are evident: a high-density network of familiar partners and a low-density network of multiple, often unfamiliar, partners. Leveraging these networks depends on the level of commitment, volume of knowledge exchange and the alignment of objectives among participant firms. Effective governance is revealed as critical for creating and capturing value within both types of network; and depends on both formal and informal mechanisms.