Using custom editors in Neos

MyCustomEditor.js

define(
[
	'emberjs',
	'Library/jquery-with-dependencies',
	'Content/Inspector/Editors/ImageEditor'
],
function (Ember, $, ImageEditor) {
	return ImageEditor.extend({

		categorization: [],

		_initializeUploader: function () {
        // This example extends the default ImageEditor from Neos, but has no functionality yet
        // do some special stuff here or override other functions
        // or just extend some basic object and build a fully custom editor
		}
	});
});

NodeTypes.yaml

'Vendor.Package:NodeType':
  properties:
    someProperty:
      ui:
        inspector:
          # Note: This uses the mapping "key" from Settings.yaml
          editor: 'Vendor.Package/Js/MyCustomEditor'

Settings.yaml

TYPO3:
  Neos:
    userInterface:
      requireJsPathMapping:
        'Vendor.Package/Js': 'resource://Vendor.Package/Public/JavaScript'

This is the bare minimum to configure a custom editor, obviously you need to fill in other stuff in the configuration and actually add functionality to your custom editor.