Seems that Crystal dosen't have Windows support yet.

docs/options.md

@@ -1179,6 +1179,69 @@ Path to uncrustify config file. i.e. uncrustify.cfg (Supported by Uncrustify)
 }
 ```
 
+####  [Crystal](#crystal) 
+
+**Supported Beautifiers**:  [`crystal`](#crystal) 
+
+**Description**:
+
+Options for language Crystal
+
+#####  [Disable Beautifying Language](#disable-beautifying-language) 
+
+**Important**: This option is only configurable from within Atom Beautify's setting panel.
+
+**Type**: `boolean`
+
+**Description**:
+
+Disable Crystal Beautification
+
+**How to Configure**
+
+1. You can open the [Settings View](https://github.com/atom/settings-view) by navigating to
+*Edit > Preferences (Linux)*, *Atom > Preferences (OS X)*, or *File > Preferences (Windows)*.
+2. Go into *Packages* and search for "*Atom Beautify*" package.
+3. Find the option "*Disable Beautifying Language*" and change it to your desired configuration.
+
+#####  [Default Beautifier](#default-beautifier) 
+
+**Important**: This option is only configurable from within Atom Beautify's setting panel.
+
+**Default**: `crystal`
+
+**Type**: `string`
+
+**Enum**:  `crystal` 
+
+**Description**:
+
+Default Beautifier to be used for Crystal
+
+**How to Configure**
+
+1. You can open the [Settings View](https://github.com/atom/settings-view) by navigating to
+*Edit > Preferences (Linux)*, *Atom > Preferences (OS X)*, or *File > Preferences (Windows)*.
+2. Go into *Packages* and search for "*Atom Beautify*" package.
+3. Find the option "*Default Beautifier*" and change it to your desired configuration.
+
+#####  [Beautify On Save](#beautify-on-save) 
+
+**Important**: This option is only configurable from within Atom Beautify's setting panel.
+
+**Type**: `boolean`
+
+**Description**:
+
+Automatically beautify Crystal files on save
+
+**How to Configure**
+
+1. You can open the [Settings View](https://github.com/atom/settings-view) by navigating to
+*Edit > Preferences (Linux)*, *Atom > Preferences (OS X)*, or *File > Preferences (Windows)*.
+2. Go into *Packages* and search for "*Atom Beautify*" package.
+3. Find the option "*Beautify On Save*" and change it to your desired configuration.
+
 ####  [C#](#c-) 
 
 **Supported Beautifiers**:  [`Uncrustify`](#uncrustify) 

src/beautifiers/crystal.coffee

@@ -9,13 +9,23 @@ module.exports = class Crystal extends Beautifier
   name: "crystal"
 
   options: {
-    Crystal: false
+    Crystal: true
   }
 
   beautify: (text, language, options) ->
+    # Seems that Crystal dosen't have Windows support yet.
+    if @isWindows
+      @Promise.reject(@commandNotFoundError(
+        'crystal'
+        {
+        link: "http://crystal-lang.org"
+        program: "crystal"
+        })
+      )
+    else
       @run("crystal", [
-      'tool'
+        'tool',
-      'format'
+        'format',
         tempFile = @tempFile("temp", text)
         ], {ignoreReturnCode: true})
         .then(=>