## Controller #####
def index
  @categories = Category.find(:all, :conditions => {:parent_id => nil})
end

## View #####
#categories
  %h1 Categories
  %table
    - @categories.each do |c|
      %tr
        %th
          = link_to c.name, c
        %td.inverted
          - c.children.each do |child|
            %li= link_to (child.name, child)
            - child.children.each do |child2|
              %i.small= '// ' + child2.name