Install Moose

Moose runs inside a Pharo image. The easiest way to get one is to use the Pharo Launcher.

Installation

Download and install the Pharo Launcher from the Pharo website.
Open the Pharo Launcher, click on New, then select a Moose image in the Moose category.

Take the highest stable version available. The Readme of the Moose project lists the current versions.
Once the image is downloaded, select it and click on Launch.
Moose opens. You should see the Pharo world with a Moose entry in the top menu bar: it gives access to all the Moose tools.

Install a specific version of Moose

Add all Moose GitHub releases to the Pharo Launcher

By default, the Pharo Launcher only lists the most recent Moose versions. If you need a specific release, you can add it as a template source:

Open the Pharo Launcher.
Open a playground (Ctrl + O, Ctrl + W).

Execute the following piece of code, after adapting the version numbers and URLs to the release you need:

| sources |

sources := {
    "Add Moose"
    PhLTemplateSource new
        type: #URLGroup;
        name: 'Moose 12';
        templates: {
        PhLTemplateSource new
            type: #URL;
            name: 'Moose12-Pharo12';
            url: 'https://github.com/moosetechnology/Moose/releases/download/v12.0.0/Moose12-stable-Pharo64-12.zip';
            yourself.
        PhLTemplateSource new
            type: #URL;
            name: 'Moose12-Pharo13';
            url: 'https://github.com/moosetechnology/Moose/releases/download/v12.0.0/Moose12-stable-Pharo64-13.zip';
            yourself.
} }.

PhLUserTemplateSources sourcesFile writeStreamDo: [ :s |
    (STON writer on: s)
        newLine: String lf;
        prettyPrint: true;
        nextPut: sources ]

Close the playground.
Select New >> Moose >> Your version.