DescriptionThe ongoing revolution enabled via containerization, virtualization, and new orchestration models has dramatically changed how applications and services are delivered and managed across the computing industry. This revolution has established a new ecosystem of tools and techniques with new, flexible and agile approaches, and has rapidly gained traction in the HPC community. In addition to HPC-optimized container runtimes, emerging technologies like Kubernetes create a new set of opportunities and challenges. While adoption is growing, there remain numerous questions regarding best practices, foundational concepts, tools, and standards. Our goal is to promote and accelerate the adoption and impact of this new ecosystem to better address HPC use cases. This workshop serves as a key venue for presenting late-breaking research, sharing experiences and best practices, and fostering collaboration in this field. Our fourth workshop iteration will continue to emphasize real-world experiences and challenges in adopting and optimizing these new approaches for HPC.