Charliecloud
charliecloud.io
What it is
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.
Spec sheet
- Purpose
- Charliecloud is a lightweight, fully unprivileged, open source container implementation for high performance computing applications.Read 9 Oct 2026 · charliecloud.io
- Support
- Users can report bugs or request features through the GitLab project and can get usage help through mailing lists and chat channels.Read 9 Oct 2026 · charliecloud.io
- License
- Charliecloud is open source software distributed under the Apache License, Version 2.0.Read 9 Oct 2026 · charliecloud.io
- Build cache
- Its layer-free build cache is based on Git rather than union mount filesystems and tarballs.Read 9 Oct 2026 · charliecloud.io
- Dockerfile support
- Charliecloud parses Dockerfiles using a formal grammar.Read 9 Oct 2026 · charliecloud.io
- Hardware integration
- At runtime, ch-run can inject host resources into containers using the Container Device Interface, including resources such as NVIDIA GPUs and Cray networking.Read 9 Oct 2026 · charliecloud.io
- Installation
- Charliecloud can be built from a release tarball or Git checkout and is also available through package managers including Spack and Fedora/EPEL.Read 9 Oct 2026 · charliecloud.io
- Notable limit
- The project states that it supports only the current release.Read 9 Oct 2026 · charliecloud.io
- Platform requirements
- Charliecloud requires Linux user namespaces for its fully unprivileged workflow; it has been run on x86-64, ARM, and Power, and is currently tested on x86_64 and ARM.Read 9 Oct 2026 · charliecloud.io
- Project membership
- Charliecloud is a member of the High Performance Software Foundation and, through it, the Linux Foundation.Read 9 Oct 2026 · charliecloud.io
- Registry compatibility
- The ch-image tool can push and pull images to registries, including GitLab Container Registry, and supports registry authentication.Read 9 Oct 2026 · charliecloud.io
- Runtime model
- It uses Linux user namespaces to run containers without privileged operations or daemons, with minimal configuration changes on computing center resources.Read 9 Oct 2026 · charliecloud.io
- Security approach
- Charliecloud does not provide a security boundary within the software and relies on the Linux kernel and userland to enforce security.Read 9 Oct 2026 · charliecloud.io
- Workflow
- It supports building images, pushing and pulling images to registries, and using accelerators such as GPUs.Read 9 Oct 2026 · charliecloud.io
Plans and prices
Charliecloud Free Open source container software; Apache License 2.0 Read 9 Oct 2026 · charliecloud.io
Strong points and limits
Strong points
- Fully unprivileged Linux containers
- Supports GPU accelerators
- Git-based layer-free cache
- Registry authentication support
- Apache License 2.0
Limits
- Linux user namespaces required
- Supports only the current release
- No software security boundary
- Linux platform only
Who it suits
Charliecloud suits HPC users who need rootless containers and accelerator access on Linux systems. It is intended for computing environments that can rely on kernel and userland security.
Verdict
Charliecloud provides rootless, daemon-free containers with image building, registry operations, and HPC hardware integration. Its Linux-only requirements and reliance on external kernel and userland security are central considerations.
Where Specifiction places it
- Container Engines#10 of 317.9
- Container Runtime Software#12 of 288.0
