• Documentation
• Support
• Community Meetings / Minutes / Roadmap
• Project License
• Guidelines for Contributing
• Code of Conduct
• Citation

Apptainer is an open source container platform designed to be simple, fast, and secure. Many container platforms are available, but Apptainer is designed for ease-of-use on shared systems and in high performance computing (HPC) environments. It features:

• An immutable single-file container image format, supporting cryptographic signatures and encryption.
• Integration over isolation by default. Easily make use of GPUs, high speed networks, parallel filesystems on a cluster or server.
• Mobility of compute. The single file SIF container format is easy to transport and share.
• A simple, effective security model. You are the same user inside a container as outside, and cannot gain additional privilege on the host system by default.

Apptainer is open source software, distributed under the BSD License.

Apptainer was formerly known as Singularity and is now a part of the Linux Foundation. When migrating from Singularity see the admin migration documentation and user compatibility documentation.

Check out talks about Apptainer and some use cases of Apptainer on our website.

To install Apptainer from source, see the installation instructions. For other installation options, see our guide.

System administrators can learn how to configure Apptainer, and get an overview of its architecture and security features in the administrator guide.

For users, see the user guide for details on how to run and build containers with Apptainer.

Community contributions are always greatly appreciated. To start developing Apptainer, check out the guidelines for contributing.

Please note we have a code of conduct. Please follow it in all your interactions with the project members and users.

Our roadmap, other documents, and user/developer meeting information can be found in the apptainer community page.

We also welcome contributions to our user guide and admin guide.

To get help with Apptainer, check out the Apptainer Help web page.

Apptainer aims to maintain support for the two most recent stable versions of Go. This corresponds to the Go Release Maintenance Policy and Security Policy, ensuring critical bug fixes and security patches are available for all supported language versions.

Apptainer can be cited using its former name Singularity.

The Singularity software may be cited using our Zenodo DOI 10.5281/zenodo.1310023:

Singularity Developers (2021) Singularity. 10.5281/zenodo.1310023 https://doi.org/10.5281/zenodo.1310023

This is an 'all versions' DOI for referencing Singularity in a manner that is not version-specific. You may wish to reference the particular version of Singularity used in your work. Zenodo creates a unique DOI for each release, and these can be found in the 'Versions' sidebar on the Zenodo record page.

Please also consider citing the original publication describing Singularity:

Kurtzer GM, Sochat V, Bauer MW (2017) Singularity: Scientific containers for mobility of compute. PLoS ONE 12(5): e0177459. https://doi.org/10.1371/journal.pone.0177459

Unless otherwise noted, this project is licensed under a 3-clause BSD license found in the license file.