Grab the latest stable release of Apptainer, submit issues, and contribute to the project at the official GitHub repository.
Quick Start Guide
Check out the quick start documentation to get Apptainer installed and set up in a hurry.
Pre-built packages are available for download as Assets under each github release for some operating systems. You will also be able to find it in EPEL for RHEL derivatives and in Fedora, although currently in those it is still under the name singularity while waiting for further apptainer validation.