Information technology (IT) advancements enabled new delivery models (i.e. Cloud Computing), thereby facilitating the emergence of new business models in the IT industry, such as Cloud platform ecosystems. With their growing acceptance and diffusion in practice, we need a deeper understanding of their IT capabilities in order to implement their business model, thereby creating and appropriating value. We draw on empirical data from four case studies of Cloud platform ecosystems utilizing a framework on IT-enabled business models for data analysis. We found four key motivations for inter-firm collaboration that each generated business model requirements specified in the context of Cloud platform ecosystems. These drive the development of unique B2B IT capabilities enabling value crea-tion and appropriation mechanisms. We propose three dyadic (relation-specific) IT customization and two network IT standardization (network-oriented) capabilities based on our cross case analysis. Fur-thermore, we describe prevalent value creation and appropriation mechanisms and suggest two addi-tional mechanisms grounded in the data: downstream capabilities and platform resourcing. We pro-vide a possible reasoning on the underlying logic of IT capabilities, value creation and appropriation of Cloud platform ecosystems.