Introduction

What are Containers?

Containers are an operating system virtualization technology used to package applications and their dependencies and run them in isolated environments. Unlike Virtual Machines, they share the host OS kernel, thus provide a lightweight method of packaging and deploying applications in a standardized way across many different types of infrastructure.

What is Apptainer?

Apptainer is a container platform. It allows you to create and run containers that package up pieces of software in a portable and reproducible way. In contrast to Docker, Apptainer does not give superuser privileges. And it can access to the GPU on a host node in native speed.

Apptainer is the Linux Foundation continuation of the open-source Singularity project. Existing Singularity images (.sif) and definition files work with Apptainer, and most installations also provide singularity as an alias for apptainer. See Singularity Compatibility for details.

You can build a container using Apptainer on your laptop, and then run it on the grid. You can also make use of many already existing container images from different sources.