...Collaboration between industry, laboratories, and academia to create an open-source, production-grade communication framework for data-centric and high-performance applications. Unified Communication X (UCX) is an award winning, optimized production proven communication framework for modern, high-bandwidth and low-latency networks. UCX exposes a set of abstract communication primitives which utilize the best of available hardware resources and offloads. These include RDMA (InfiniBand and RoCE), TCP, GPUs, shared Memory, and network atomic operations. UCX facilitates rapid development by providing a high-level API, masking the low-level details, while maintaining high-performance and scalability. ...