Software product development requires connecting of specialized information and know-how. Therefore, planning and production are widely done in networked projects. This chapter studies inter-firm collaboration to explore the role of face-to-face meetings and information and communication technology in knowledge transfer in product development by using case studies of software companies in Oulu, Finland. Clusters are important in forming trust and mutual understanding. Thus, a compact city region and effective social networks are beneficial for inter-firm collaboration. However, information and communication technology is very valuable for routine communication and documentation, but also in distance collaboration. Geographical distance affects inter-firm collaboration in terms of practical arrangements, such as working hours, yet cultural differences bring additional challenges. This chapter considers and scrutinizes social networking in collaborative product development, and the role of clusters and information and communication technology in such development, as among the key success factors.