In a world of smart networked devices, wearables, sensors and actuators, transparent and secure access to and usage of the available resources across various IoT domains is crucial to satisfy the needs of an increasingly connected society. The current IoT ecosystem is however fragmented: a series of vertical solutions exist today which, on the one hand, integrate connected objects within local environments using purpose-specific implementations and, on the other hand, connect smart spaces with a back-end cloud hosting dedicated often proprietary software components. symbIoTe (symbiosis of smart objects across IoT environments) comes to remedy this fragmented environment by providing an abstraction layer for a “unified view” on various platforms and their resources so that platform resources are transparent to application designers and developers. In addition, symbIoTe also chooses a challenging task to implement IoT platform federations so that they can securely interoperate, collaborate and share resources for the mutual benefit, and what is more, support the migration of smart objects between various IoT domains and platforms, i.e., “smart object roaming”. symbIoTe will achieve all of the above by designing and implementing an Open Source mediation prototype. In light of the above, symbIoTe opens up the potential for innovative business models that are incrementally deployable. This is especially important for SMEs who are symbIoTe’s primary target group. Moreover, symbIoTe removes the strict separation between IoT islands to create an environment which i) has significant impact on the market since it bridges individual efforts and investments, ii) is attractive for a heterogeneous user group, iii) matches the dynamicity of modern life due to ease of use and iv) is helpful for various business, home and public infrastructure use cases.