X-TREME 6G proposal relies on a unique industry led consortium to provide a foundational open microelectronics platform in Europe with the objective to create and design key disruptive next generation chiplets and chipsets for 6G use cases. The idea is to break-up the full potential of best-in-class Silicon BiCMOS, InP and heterogeneous 3D integration for high capacity radio access technologies such as wireless back-hauling at sub-TeraHertz frequencies, Joint Communication And Sensing, Non Terrestrial Networks and Network as a Sensor. New classes of chipsets will unleash the full potential of 6G and enable the emergence of new applications through specific developments for the underpinning novel microelectronic technologies. X-TREME 6G valorizes also resource efficient 6G algorithms and an ML/AI software toolbox for computationally efficient silicon-ready baseband extensions. Part of the SNS “Microelectronic Lighthouse” visionary initiative, the proposal’s ambition is to establish and maintain a sustainable open platform for the duration of the SNS program and beyond, to support 6G verticals. By nurturing the links with the emerging Chips JU pilot lines, the platform acts as a first fabric to accelerate joint initiatives between SNS and Chips JUs. In a nutshell, X-TREME 6G will provide tangible contributions towards an experimentation EU framework for 6G, demonstrating the full benefit of the newly developed chipsets and chiplets for a set of emerging 6G high potential use cases (wireless back-hauling, JCAS, NTN, NaS); while being open to dynamically support the emerging 6G ecosystem (SMEs, Industries, Service Providers, Government etc.) and evaluate additional 6G challenges and expectations. By strengthening and extending the 6G functionality and microelectronics supply chain, X-TREME 6G contributes towards a network-centric democratized and open 6G ecosystem able to release the current hyperscaler’s market embrace, while empowers European Industry at large.