Digital Infrastructures and the future Internet including 5G and beyond technologies are the main enabling factors contributing to the digital transformation of our society. The COVID-19 crisis has demonstrated the vital role of digital infrastructures and showed they should be reinforced. Their design, deployment and operation are critical, calling for a scientific instrument to support the research in this domain for computer science and infrastructure researchers, as well as for data driven scientific applications involving interdisciplinary aspects. This report summarizes the analysis of the current technological status and capabilities of existing ICT Research Infrastructures in Europe as it stands for the beginning of 2021. The analysis has been performed by the authors and reflects the knowledge gathered and processed by the authors using public documentation (e.g., available on the projects’ websites) and through personal communication between sources of information in particular Member States. This report does not intend to replace and override documentation prepared by larger communities and organizations (e.g., the European Commission, ESFRI or e-IRG). Instead, this report complements existing efforts made so far with a primary focus on ICT technologies related to SLICES and with new information received from Member States, not necessarily already included in above mentioned state-of-the-art reports. This report has been prepared by SLICES-DS Partners with support and advice from the following organisations: Poznan Supercomputing and Networking Center (Poland), Sorbonne University (France), INRIA (France), MTA Sztaki (Hungary), Technical University of Munich (Germany), UPV/EHU (Spain), UC3M (Spain), UCLAN (Cyprus), Université Du Luxembourg (Luxembourg), SIMULA (Norway), CNR (Italy), Mandat International (Switzerland), KTH (Sweden), University of Gent (Belgium) and RNP (Brazil). The document is intended at ESFRI stakeholders, policy makers, researchers and RI managers.