The quest for something less noisy than XAML

If WPF used YAML.yml

%YAML 1.2
---
UserControl:
  Name: AddressBookControl
  BackgroundColor: White
  Controls:
    StackPanel:
      Children:
        - Label:   {Color: Blue, Content: This is the title}
        - TextBox: {Text: Hello World, FontSize: 14}
        - Button:  {Width: 100, Height: 23, Content: Click Me!}

        - Grid:
            Width: 400px
            Margin: 4
            ColumnDefinitions: [ColumnDefinition, ColumnDefinition, ColumnDefinition]
            RowDefinitions:    [RowDefinition, RowDefinition]
            Children:
              - TextBlock: {Grid.Column: 0, Text: Foo}
              - TextBlock: {Grid.Column: 1, Text: Bar}
              - TextBlock: {Grid.Column: 2, Text: Quotes are not often required}

              - TextBlock: {Grid.Column: 0, Grid.Row: 1, Text: Foo}
              - TextBlock: {Grid.Column: 1, Grid.Row: 1, Text: Bar}
              - TextBlock: {Grid.Column: 2, Grid.Row: 1, Text: Quotes are not often required}