# Elm

Compiler for Elm, a functional language for reliable webapps.

Repository: https://github.com/elm/compiler
Canonical: https://ross.abutalabs.com/products/elm
Homepage: https://elm-lang.org/
Language: Haskell
License: BSD-3-Clause
License Family: permissive
Topics: elm, compiler
Last push: 2026-08-26T07:47:17+00:00
Link (homepage): https://elm-lang.org/

## Health v2 (maintenance only)
Score: 86/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 60, longevity 100
- inputs: {"age_days": 5249, "days_push": 7, "days_rel": 58, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 7886, forks 688 (observed 2026-08-28T04:10:08.584012+00:00)

## What it is
The official compiler for Elm, a statically typed functional programming language designed for building reliable web applications that compile down to JavaScript. Written in Haskell, it emphasizes friendly error messages, strict type safety, and a practical guarantee of no runtime exceptions in Elm code.

## Use cases
- compile elm source code to optimized javascript bundles
- build frontend web apps with strong static typing
- find a language that eliminates runtime exceptions in production
- learn functional programming for web development
- set up the elm toolchain locally with make, repl, and package management
- migrate a javascript frontend to a more reliable typed language

## When to choose
- you want guaranteed no-runtime-exceptions frontend code with a friendly compiler
- you prefer the Elm Architecture pattern for state management in web UIs
- you are teaching or learning typed functional programming in a web context
- you value compiler-enforced refactoring and semantic versioning of packages

## When to avoid
- you need deep interop with the npm ecosystem or existing javascript libraries without ports
- you need server-side rendering or backend execution, since Elm targets the browser
- you require frequent language changes or a large rapidly evolving ecosystem
- your team depends on dynamic typing or gradual typing workflows

## Facets
- artifact type: cli-tool
- maturity: stable
- function: compiler, programming-language, type-system, developer-tools
- domain: programming-languages, compilers, web-development, frontend
- platform: windows, browser, cli, cross-platform
- tags: elm, functional-programming, static-typing, no-runtime-exceptions, javascript-compilation, haskell, elm-architecture, frontend-language, linux, macos

## Member repositories
- elm/compiler (main) score 86
- elm/core (sdk) score 32
- elm/elm-lang.org (docs) score 73

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:08.584012+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 2026-08-29T17:33:42.550282+00:00, confidence not recorded.
  - readme: https://github.com/elm/compiler (fetched 2026-08-28T04:10:08.584012+00:00, sha 6cc5cdda5224)
  - homepage: https://elm-lang.org/ (fetched 2026-08-29T08:30:09.047986+00:00, sha 4e80bc79f920)
- Data as of 2026-08-30T08:39:29.467469+00:00.