.row
  %ul.nav
    %li
      %a{:href => "/rubyx/layers.html"} Layers of RubyX
    %li
      %a{:href => "/rubyx/memory.html"} Memory
    %li
      %a{:href => "/rubyx/threads.html"} Threads
    %li
      %a{:href => "/rubyx/optimisations.html"} Optimisation ideas