Skip to content
SPECIFICTION
Get listed

Elm Reactor

elm-lang.org

WebWindowsmacOSLinux
Visit elm-lang.org
Spec score 7.0 #131 of 138 in Coding Playgrounds

Spec sheet

Purpose
Elm is a functional language that compiles to JavaScript and is designed for websites and web apps.Read 12 Oct 2026 · guide.elm-lang.org
License
The repository lists a BSD-3-Clause license.Read 4 Oct 2026 · github.com
Founded
2013Read 19 Oct 2026 · elm-lang.org
Compilation
`elm make` compiles Elm code to HTML or JavaScript.Read 12 Oct 2026 · guide.elm-lang.org
Compiler messages
The guide says `elm make` produces the same messages as the online editor and `elm reactor`.Read 4 Oct 2026 · guide.elm-lang.org
Debugging limit
The project page says time travel is not available in `elm-reactor` at present.Read 4 Oct 2026 · github.com
Feedback
The guide invites users to report unhelpful compiler messages through a linked GitHub page.Read 12 Oct 2026 · guide.elm-lang.org
Help
The guide says users can run `elm --help` or command-specific help, such as `elm make --help`, to see available commands and flags.Read 12 Oct 2026 · guide.elm-lang.org
Installation platforms
The Elm installation guide links to installation options for Mac, Linux, and Windows.Read 4 Oct 2026 · guide.elm-lang.org
Language guarantees
The guide lists no runtime errors in practice, friendly error messages, reliable refactoring, and automatically enforced semantic versioning for Elm packages as benefits of Elm.Read 12 Oct 2026 · guide.elm-lang.org
Learning
The Elm guide teaches programming fundamentals and how to build interactive apps with The Elm Architecture.Read 12 Oct 2026 · guide.elm-lang.org
Local development
Running `elm reactor` at a project’s root starts a server at localhost:8000 where users can view Elm files.Read 12 Oct 2026 · guide.elm-lang.org
Local server
Running `elm reactor` at a project’s root starts a server at `http://localhost:8000`.Read 4 Oct 2026 · guide.elm-lang.org
More advanced projects
The guide recommends `elm make` as the general compilation method when a project becomes too advanced for `elm reactor`.Read 4 Oct 2026 · guide.elm-lang.org
Online editor
The Elm guide links to an online editor where users can try Elm code.Read 12 Oct 2026 · guide.elm-lang.org
Packages
Elm packages are hosted at package.elm-lang.org, and `elm install` adds dependencies to a project’s `elm.json` file.Read 12 Oct 2026 · guide.elm-lang.org
Preview
You can navigate to an Elm file served by the local server and see what it looks like.Read 4 Oct 2026 · guide.elm-lang.org
Project organization
The Elm Software Foundation describes Elm as connecting web development with academic research on functional programming languages.Read 4 Oct 2026 · foundation.elm-lang.org
Project status
The `elm-reactor` repository was archived on August 23, 2018 and is read-only.Read 4 Oct 2026 · github.com
Supported desktop systems
The installation guide provides links for Mac, Linux, and Windows.Read 12 Oct 2026 · guide.elm-lang.org

Where Specifiction places it

Alternatives to Elm ReactorAll alternatives →