diff --git a/generate_atomic_docs.rb b/generate_atomic_docs.rb
index af09ef60..e9fa56f0 100755
--- a/generate_atomic_docs.rb
+++ b/generate_atomic_docs.rb
@@ -7,44 +7,112 @@ require 'json'
 
 def attack_technique_library
   @attack_json ||= begin
+    # load the full attack library
     local_attack_json_to_try = "#{File.dirname(__FILE__)}/enterprise-attack.json"
-    if File.exists? local_attack_json_to_try
+    parsed = if File.exists? local_attack_json_to_try
       JSON.parse File.read(local_attack_json_to_try)
     else
       JSON.parse open('https://raw.githubusercontent.com/mitre/cti/master/enterprise-attack/enterprise-attack.json').read
     end
+
+    # pull out the attack pattern objects
+    parsed.fetch("objects").select do |item| 
+      item.fetch('type') == 'attack-pattern' && item.fetch('external_references', []).select do |references|
+        references['source_name'] == 'mitre-attack'
+      end
+    end
+
   end
 end
 
 def attack_technique_info(technique_id)
-  attack_technique_library.fetch("objects").find do |item| 
-    item.fetch('type') == 'attack-pattern' && item.fetch('external_references', []).find do |references|
-      references['source_name'] == 'mitre-attack' && references['external_id'] == technique_id.upcase
+  attack_technique_library.find do |item| 
+    item.fetch('external_references', []).find do |references|
+      references['external_id'] == technique_id.upcase
     end
   end
 end
 
-def generate_docs!(path)
-  atomic_yaml = YAML.load(File.read path)
+def all_techniques_by_tactic
+  @all_techniques_by_tactic ||= begin
+    all_techniques_by_tactic = Hash.new {|h, k| h[k] = []}
+    attack_technique_library.each do |technique|
+      tactic = technique.fetch('kill_chain_phases', []).find {|phase| phase['kill_chain_name'] == 'mitre-attack'}.fetch('phase_name')
+      all_techniques_by_tactic[tactic] << technique
+    end
+    all_techniques_by_tactic
+  end
+end
 
+def generate_docs!(atomic_yaml, output_doc_path)
   technique = attack_technique_info(atomic_yaml.fetch('attack_technique'))
   technique['identifier'] = atomic_yaml.fetch('attack_technique').upcase
 
   template = ERB.new File.read("#{File.dirname(__FILE__)}/atomics/atomic_doc_template.md.erb"), nil, "-"
   generated_doc = template.result(binding)
 
-  output_doc_path = path.gsub(/.yaml/, '.md')
   print " => #{output_doc_path} => "
   File.write output_doc_path, generated_doc
 end
 
+def update_index_mapping(atomic_yaml, techniques_by_tactic)
+  technique = attack_technique_info(atomic_yaml.fetch('attack_technique'))
+  technique.fetch('kill_chain_phases', []).select {|phase| phase['kill_chain_name'] == 'mitre-attack'}.each do |tactic|
+    techniques_by_tactic[tactic.fetch('phase_name')] << technique
+  end
+end
+
+def generate_indices!(techniques_by_tactic)
+  ordered_tactics = [
+    'initial-access',
+    'execution',
+    'persistence',
+    'privilege-escalation',
+    'defense-evasion',
+    'credential-access',
+    'discovery',
+    'lateral-movement',
+    'collection',
+    'exfiltration',
+    'command-and-control',
+  ]
+
+  result = ''
+  result += "| #{ordered_tactics.join(' | ')} |\n"
+  result += "|#{'-----|' * ordered_tactics.count}\n"
+
+  all_techniques_in_tactic_order = []
+  ordered_tactics.each do |tactic|
+    all_techniques_in_tactic_order << all_techniques_by_tactic[tactic]
+  end
+  max_tactics = all_techniques_in_tactic_order.collect(&:count).max
+  all_techniques_in_tactic_order.each {|techniques| techniques.concat(Array.new(max_tactics - techniques.count, nil))}
+
+  p all_techniques_in_tactic_order.count
+  all_techniques_in_tactic_order.transpose.each do |row|
+    p row, row.class
+    result += "| #{row.collect {|t| t['name'] if t}.join(' | ')} |\n"
+  end
+
+  # all_techniques_by_tactic.to_a.transpose[1..-1].first.each do |techniques|
+  #   p techniques, techniques.count, '-----'
+  #   result += "| #{techniques.collect {|t| t['name']}.join(' | ')} |\n"
+  # end
+  File.write "#{File.dirname(__FILE__)}/atomics/index.md", result
+end
+
 oks = []
 fails = []
+techniques_by_tactic = Hash.new {|h, k| h[k] = []}
 
 Dir["#{File.dirname(__FILE__)}/atomics/t*/t*.yaml"].sort.each do |path|
   begin
     print "Generating docs for #{path}"
-    generate_docs! path
+    atomic_yaml = YAML.load(File.read path)
+
+    generate_docs! atomic_yaml, path.gsub(/.yaml/, '.md')
+    update_index_mapping atomic_yaml, techniques_by_tactic
+    
     puts "OK"
   rescue => ex
     fails << path
@@ -52,6 +120,8 @@ Dir["#{File.dirname(__FILE__)}/atomics/t*/t*.yaml"].sort.each do |path|
   end
 end
 
+generate_indices! techniques_by_tactic
+
 puts
 puts "Generated docs for #{oks.count} techniques, #{fails.count} failures"