InfiniBand (IB), High-speed Ethernet (HSE), RoCE, Omni-Path, EFA, and Slingshot technologies are generating a lot of excitement towards building next generation High-End Computing (HEC) systems including clusters, datacenters, file systems, storage, cloud computing, Big Data and Deep Learning systems. This tutorial will provide an overview of these emerging technologies, architectural features, current market standing, and suitability for designing HEC systems. It will start with a brief overview of IB, HSE, RoCE, Omni-Path, EFA, Slingshot, and Omni-Path. In-depth overview of the architectural features of these technologies, their similarities and differences, and the associated protocols will be presented. An overview of the emerging NVLink, NVLink2, and NVSwitch architectures will also be given. Next, an overview of the OpenFabrics and Libfabrics stack will be presented. Hardware/software solutions and the market trends behind these networking technologies will be highlighted. Finally, sample performance numbers of these technologies and protocols for different environments will be presented.