For those cordial with CoffeeScript, there's Hamlet[1] (which is based on/inspired by HAML[2]). It's a pretty nice declarative-esque UI library. From their home page, here's a sample:

  %label
    Search:
    %input(value=@search type="text")
  %label
    Sort by:
    %select(value=@sortBy @options)
  %ul
    -each @sorted, ->
      %li.phone(@class)
        %img(@src)
        .name= @name
        .description= @snippet

1 - http://hamlet.coffee

2 - http://haml.info