Detailed installation steps for all supported platforms can be found in the official Apptainer installation documentation.

Installing on Windows and Mac

To install Apptainer on a Mac or a Windows computer, you need to have a virtual Linux computer running, and that is where you would do the installation.

• On Windows, you can create a virtual Linux computer using the Windows Subsystem for Linux. The latest version is called WSL 2. If you haven't enabled it on your computer, you need to do that first, and then you can install Apptainer. The Apptainer installation instructions you use would depend on which flavor of Linux you installed in your WSL. Ubuntu is recommended.
• On a Macintosh, you can run a virtual Linux computer using Lima, a lightweight, command-line Linux environment that is recommended for Apptainer. To install Lima, you would need to have Homebrew. If you don't have Homebrew, you may need to install that first. As an alternative, you could try installing UTM to get a full-desktop experience with a Linux VM on Apple Silicon.

Installing on Linux

If you are on a Linux computer, like Ubuntu or Red Hat (or its free variants such as Rocky Linux and AlmaLinux), there are specific sections in the installation documentation that cover each distribution. Typically, you would need to add a repository to your environment from which software can be installed, because the Apptainer package is in that particular repository. Once you add the repository to your environment, you can install the Apptainer package. To give an example, for Red Hat and its variants, you might need to add EPEL. In some versions of Rocky Linux or AlmaLinux, you might find you need to use a GitHub-hosted RPM file to install. In all cases, you need to be an administrator on your Linux system in order to perform the installation.