International Collaboration plans towards a multi-TeV muon collider

This report briefly summarizes the achievements performed during the four years-time span by this network set-up during the past European Strategy for Particle Physics Update (2020) and later by the international community within the Muon Collider Collaboration (IMCC) hosted at CERN. The path to promote the innovative accelerator technology of bright muon beams and the submission of the input documents to the on-going update of the European Strategy for Particle Physics is part of the Accelerator R&D Roadmap, approved and implemented by CERN Council and reviewed by the CERN Laboratories Directors Group (LDG) in February 2025. The MUon colliders STrategy network (MUST) supported IMCC to develop a multi-TeV muon collider design and the required technology R&D plans, needed to demonstrate the feasibility of this future project.  R&D plans require enabling accelerator technologies (magnets, RF and materials) also studied by other I.FAST WPs, and new dedicated test facilities and a more complex muon cooling demonstrator.