# Apptainer

Apptainer: Application containers for Linux

Repository: https://github.com/apptainer/apptainer
Canonical: https://ross.abutalabs.com/products/apptainer
Homepage: https://apptainer.org
Language: Go
License: NOASSERTION
License Family: other
Topics: linux, containers, science, hpc, apptainer, singularity, singularity-container, rootless-containers
Last push: 2026-08-24T15:58:24+00:00
Link (homepage): https://apptainer.org
Link (site_page): https://apptainer.org/documentation

## Health v2 (maintenance only)
Score: 93/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 82, longevity 100
- inputs: {"age_days": 1737, "days_push": 9, "days_rel": 43, "gap_med": 35, "n_releases_24m": 14}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1949, forks 182 (observed 2026-08-28T04:05:58.078365+00:00)

## What it is
Apptainer (formerly Singularity) is an open-source container platform designed for secure, portable, and reproducible containers on shared systems and HPC environments. It uses an immutable single-file SIF image format, runs rootless by default, and can import Docker/OCI images.

## Use cases
- run containers on an HPC cluster without root privileges
- package scientific software into a portable single-file container
- convert Docker images to run on shared Linux systems
- encrypt container images for secure workload distribution
- reproducibly archive and share compute workloads
- use GPUs and parallel filesystems inside containers

## When to choose
- you need rootless containers on multi-user shared systems or HPC clusters
- you want a single-file, signable, encryptable container image format
- you need to run existing Docker/OCI containers unprivileged on Linux

## When to avoid
- you need Docker-style daemon-based workflows or Docker Compose orchestration
- you primarily target Windows or macOS desktops
- you need Kubernetes-native container images with OCI tooling only

## Facets
- artifact type: application
- maturity: active
- function: container-runtime, security, cryptography, cli
- domain: developer-tools, cloud-computing, self-hosted
- platform: cli
- tags: hpc, rootless-containers, sif-image-format, reproducibility, docker-compatibility, singularity, scientific-computing, containers, linux, gpu

## Member repositories
- apptainer/apptainer (main) score 93
- apptainer/singularity (mirror) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:58.078365+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:20:07.013071+00:00, confidence not recorded.
  - readme: https://github.com/apptainer/apptainer (fetched 2026-08-28T04:05:58.078365+00:00, sha f21471fdf4a7)
  - homepage: https://apptainer.org (fetched 2026-08-29T10:03:06.052112+00:00, sha 9e5fd397dbfa)
  - site_page: https://apptainer.org/documentation (fetched 2026-08-29T10:03:06.072992+00:00, sha 4d19bda211f3)
- Data as of 2026-08-30T08:39:29.467469+00:00.