Jekyll filters to help with hashes.

tests.rb

@context = { 'myhash' => { 'b' => 'B', 'a' => 'A', 'c' => 'C' } }
@template = Liquid::Template.parse("{{ myhash | keys | to_ul }}")
@template.render(@context)  # => "<ul><li>b</li><li>a</li><li>c</li></ul>"
@template = Liquid::Template.parse("{{ myhash | keys | sort | to_ul }}")
@template.render(@context)  # => "<ul><li>a</li><li>b</li><li>c</li></ul>"

toolbox.rb

module Jekyll
  module Toolbox
    def keys(hash)
      hash.keys
    end
    def to_ul(collection)
      result = ''
      result << "<ul>"
      collection.each do |item|
        result << "<li>#{item}</li>"
      end
      result << "</ul>"
      result
    end
  end
end

Liquid::Template.register_filter(Jekyll::Toolbox)