XIFI will establish a sustainable marketplace for trial infrastructures and Future Internet services.XIFI will achieve this vision by integrating and federating a multiplicity of heterogeneous environments – starting from the generic and specific enablers provided by the FI-WARE core platform and the FI-PPP use cases and early trials.Through this approach XIFI will demonstrate and validate the potential and capabilities of a unified market for Future Internet facilities overcoming a number of existing limitations to the current set of Future Internet experimental infrastructures available across Europe, such as fragmentation, interoperability and scalability. XIFI will also extend its efforts to include the results of other Future Internet services and R&D work.Initially the federation of infrastructures will consist of a core backbone five nodes located in five different European countries enabled with the Technology Foundation services (from the FI-PPP project FI-WARE) to be ready before the start of FI-PPP phase 3 (at month 12 of XIFI). This initial set will be enlarged during the second year with new use cases and collaborating local and regional infrastructures.XIFI will provide significant added value to Future Internet service and application developers. Specifically XIFI will:• facilitate unified access to large-scale infrastructures by providing a single entry point for users• provide access to generic enablers with assured QoS and reliability that go beyond best effort• offer a federation service through which the infrastructures can offer their capabilities using new and existing business models• enable infrastructures to be shared across different use casesXIFI will provide training, support and assistance including integration guidelines and the promotion of best practice between large-scale trials and infrastructure nodes. These activities aim at facilitating the uptake and continued use of the FI-PPP results.