This book constitutes the refereed post-conference proceedings of 13 workshops held at the 33rd International ISC High Performance 2018 Conference, in Frankfurt, Germany, in June 2018: HPC I/O in the Data Center: 4th HPC-IODC Workshop; ExaComm: 4th International Workshop on Communication Architectures for HPC, Big Data, Deep Learning and Clouds at Extreme Scale; 13th Workshop on Virtualization in High-Performance Cloud Computing (VHPC 2018); International Workshop on OpenPOWER for HPC (IWOPH 2018); Third International Workshop on In Situ Visualization: Introduction and Applications; Third International Workshop on Data Reduction for Big Scientific Data (DRBSD-3); Numerical Reproducibility at Exascale 2018 (NRE2018); Wopsss 18; Many-Core Computing on Intel Processors: Applications, Performance and Best-Practice Solutions; OpenSuCo: Open Source Supercomputing; Second ISC HPC Applications in Precision Medicine Workshop; Workshop on Performance Portable Programming Models for Accelerators (P^3MA); and Approximate and Transprecision Computing on Emerging Technologies (ATCET). The 53 full papers and 11 short papers presented were carefully reviewed and selected from 80 submissions. They cover all aspects of research, development, and application of large-scale, high performance experimental and commercial systems. Topics include HPC computer architecture and hardware; programming models, system software, and applications; solutions for heterogeneity, reliability, power efficiency of systems; virtualization and containerized environments; big data and cloud computing; articial intelligence; as well as international collaborations.