Apptainer: Application Containers for Linux

Wish these sort of projects would do a better job articulating what the value proposition is over leading existing ones.

Like why should I put time into learning this instead of rootless podman? Aside from this secret management thing it sounds like same feature set

You should put time into learning this if you are going to be running HPC jobs on clusters, because some HPC clusters support this for jobs and not much else.

This project is way older than (rootless) podman.

So is this popular in science or data analysis / forecasting or something like that?

I'm not familiar with it (I don't know if it changed names or just didn't notice)

From the Introduction [1]

    Many container platforms are available, but Apptainer is focused on:

    Verifiable reproducibility and security, using cryptographic signatures, an immutable container image format, and in-memory decryption.

    Integration over isolation by default. Easily make use of GPUs, high speed networks, parallel filesystems on a cluster or server by default.

    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. Read more about Security in Apptainer.

[1] https://apptainer.org/docs/user/main/introduction.html

Used to be called “Singularity”

But I guess aren't their premise just the same though? I wonder how different "learning" apptainer is compared to "learning" podman given atleast in podman with podman-compose and many other such things, podman just is really equivalent to docker in a lot of scenarios with a 1:1 bind mostly

I don't think people use it for reproducible environments on their own machines the same way Docker is sometimes used, I've mostly encountered it in academic compute clusters as a way to install the libraries/languages you're using onto the cluster in an easy to remove way. So it's popular in HPC clusters specifically and not really tied to a field of research beyond that.