Charliecloud vs Podman

Charliecloud is free, open-source container software for high-performance computing on Linux. It runs containers without privileged operations or daemons by using Linux user namespaces, with minimal configuration changes on computing-center resources. Users can build images, push and pull them to registries, and use accelerators such as GPUs. Its layer-free build cache is based on Git rather than union-mount filesystems and tarballs, and Dockerfiles are parsed with a formal grammar. The ch-image tool supports registry authentication and registries including GitLab Container Registry. At runtime, ch-run can inject host resources through the Container Device Interface, including NVIDIA GPUs and Cray networking. Installation is available from a release tarball, Git checkout, Spack, or Fedora/EPEL. Charliecloud requires Linux user namespaces and has been run on x86-64, ARM, and Power; current testing covers x86_64 and ARM. It is distributed under Apache License, Version 2.0. The project supports only the current release and provides no internal security boundary.

Podman manages containers, pods, and images, with workflows for finding, running, building, and sharing container workloads. It is a free, daemonless container engine with a command line comparable to Docker’s CLI; most commands can run as a regular user without additional privileges. Podman Desktop adds a graphical application for installing and working with Podman and other container engines on Windows, macOS, and Linux. It can build images from Dockerfiles or Containerfiles, pull images from remote repositories, and manage accounts for pushing images to registries. Podman can run Kubernetes YAML locally, generate YAML from pods, and deploy to existing Kubernetes environments. It can find and pull containers from Docker Hub, Quay.io, internal registries, or vendors. On macOS and Windows it listens for Docker API clients. The project lists integrations including Visual Studio Code, Cirrus CLI, GitHub Actions, and kind. Podman is licensed under Apache License 2.0. Its security foundations include rootless and daemonless containers, SELinux support, network policy enforcement, and immutable containers.