# appc/spec

App Container Specification and Tooling (archived, see https://github.com/rkt/rkt/issues/4024)

Repository: https://github.com/appc/spec
Canonical: https://ross.abutalabs.com/products/appc-spec
Language: Go
License: Apache-2.0
License Family: permissive
Archived: true
Last push: 2018-01-24T15:52:25+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4285, "days_push": 3143, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1252, forks 142 (observed 2026-08-28T04:04:08.477265+00:00)

## What it is
The App Container (appc) specification and Go tooling, defining an image format (ACI), runtime environment, and discovery mechanism for application containers. It was the predecessor to the OCI container standards and is no longer actively developed.

## Use cases
- work with appc ACI container images
- verify and sign container images cryptographically
- understand the appc container specification
- maintain legacy rkt-based container tooling
- study the history of container image format standards
- implement appc image discovery

## When to choose
- you maintain legacy software that depends on the appc/ACI format
- you need historical reference for how appc compared to OCI specifications

## When to avoid
- starting any new container project - use OCI image and runtime specifications instead
- you need signing and dependency features not covered by OCI - consider alternatives like sigstore
- you need actively maintained tooling or community support

## Facets
- artifact type: library
- maturity: abandoned
- function: container-runtime, cryptography, developer-tools
- domain: cloud-computing
- platform: go, cross-platform
- tags: appc, aci, container-image-format, container-specification, archived, oci-predecessor, containers, devops, linux

## Member repositories
- appc/spec (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:08.477265+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 2026-08-30T05:07:32.257959+00:00, confidence not recorded.
  - readme: https://github.com/appc/spec (fetched 2026-08-28T04:04:08.477265+00:00, sha 823ff89f5486)
- Data as of 2026-08-30T08:39:29.467469+00:00.