# swiftlang/swift-corelibs-foundation

The Foundation Project, providing core utilities, internationalization, and OS independence

Repository: https://github.com/swiftlang/swift-corelibs-foundation
Canonical: https://ross.abutalabs.com/products/swift-corelibs-foundation
Language: C
License: Apache-2.0
License Family: permissive
Last push: 2026-08-25T07:35:45+00:00

## Health v2 (maintenance only)
Score: 74/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 28, longevity 100
- inputs: {"age_days": 3950, "days_push": 8, "days_rel": 466, "gap_med": 80.5, "n_releases_24m": 3}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5438, forks 1184 (observed 2026-08-28T04:09:18.169045+00:00)

## What it is
The Swift Foundation project providing core utility classes, data structures, internationalization, and OS-independent APIs for the Swift language. It supplies the Foundation framework implementation for non-Darwin platforms where no Objective-C runtime exists.

## Use cases
- use Foundation APIs like URL, Data, and JSONDecoder on Linux
- port Swift code from macOS to non-Apple platforms
- get internationalization and locale support in Swift apps
- access NSObject and NSKeyedArchiver compatibility APIs
- build cross-platform Swift server or CLI applications

## When to choose
- you are developing Swift software for Linux, Windows, or other non-Darwin platforms
- you need Foundation's core types and internationalization outside Apple operating systems
- you maintain legacy Swift code relying on pre-Swift Foundation APIs like NSObject

## When to avoid
- you are building apps for macOS, iOS, or other Apple platforms - use the OS-provided Foundation instead
- you need exact Objective-C Foundation behavior - this compatibility implementation is best-effort only

## Facets
- artifact type: library
- maturity: active
- function: internationalization, serialization, date-time, file-system, json, parser
- domain: developer-tools, programming-languages, cross-platform
- platform: windows, cross-platform
- tags: swift, foundation-framework, standard-library, icu, nsobject, toolchain, localization, linux

## Member repositories
- swiftlang/swift-corelibs-foundation (main) score 74

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:18.169045+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 2026-08-29T17:56:52.190443+00:00, confidence not recorded.
  - readme: https://github.com/swiftlang/swift-corelibs-foundation (fetched 2026-08-28T04:09:18.169045+00:00, sha 4e81c1979b9f)
- Data as of 2026-08-30T08:39:29.467469+00:00.