diff --git a/app/assets/javascripts/editor/editor.js.erb b/app/assets/javascripts/editor/editor.js.erb
index e3e34462..2d145e34 100644
--- a/app/assets/javascripts/editor/editor.js.erb
+++ b/app/assets/javascripts/editor/editor.js.erb
@@ -155,9 +155,9 @@ configureEditors: function () {
     if (!same) {
       this.publishCodeOceanEvent("codeocean_editor_paste", {
         text: pasteObject.text,
+        codeocean_user_id: $('#editor').data('user-id'),
         exercise: $('#editor').data('exercise-id'),
         file_id: "1"
-
       });
     }
   },
@@ -390,9 +390,7 @@ configureEditors: function () {
 
       var payload = {
         user: {
-          type: 'User',
-          uuid: $('#editor').data('user-id'),
-          external_id: $('#editor').data('user-external-id')
+          uuid: $('#editor').data('user-external-id')
         },
         verb: {
           type: eventName
diff --git a/app/assets/javascripts/editor/submissions.js.erb b/app/assets/javascripts/editor/submissions.js.erb
index 467c2cd7..20d8cd10 100644
--- a/app/assets/javascripts/editor/submissions.js.erb
+++ b/app/assets/javascripts/editor/submissions.js.erb
@@ -75,6 +75,8 @@ CodeOceanEditorSubmissions = {
     }
     // toggle button states (it might be the case that the request for comments button has to be enabled
     this.toggleButtonStates();
+
+    this.updateSaveStateLabel();
   },
 
   /**
@@ -200,12 +202,15 @@ CodeOceanEditorSubmissions = {
     }
   },
 
-  autosave: function () {
+  updateSaveStateLabel: function() {
     var date = new Date();
     var autosaveLabel = $(this.autosaveLabel);
     autosaveLabel.parent().css("visibility", "visible");
     autosaveLabel.text(date.getHours() + ':' + date.getMinutes() + ':' + date.getSeconds());
     autosaveLabel.text(date.toLocaleTimeString());
+  },
+
+  autosave: function () {
     this.autosaveTimer = null;
     this.createSubmission($('#autosave'), null);
   }
diff --git a/app/assets/stylesheets/request-for-comments.css.scss b/app/assets/stylesheets/request-for-comments.css.scss
index cbaf9d36..6448e6e7 100644
--- a/app/assets/stylesheets/request-for-comments.css.scss
+++ b/app/assets/stylesheets/request-for-comments.css.scss
@@ -17,3 +17,50 @@
   width: 100%;
   height: 200px;
 }
+
+.ace_tooltip {
+  display: none !important;
+}
+
+p.comment {
+  width: 400px;
+}
+
+.popover-header {
+  width: 100%;
+  overflow: hidden;
+  padding-bottom: 10px;
+  margin: auto;
+}
+
+.popover-username {
+  font-weight: bold;
+  width: 60%;
+  float: left;
+}
+
+.popover-date {
+  text-align: right;
+  color: #008cba;
+  margin-left: 60%;
+  font-size: x-small;
+}
+
+.popover-updated {
+  text-align: right;
+  margin-left: 60%;
+  font-size: x-small;
+}
+
+.popover-comment {
+  word-wrap: break-word;
+  margin-bottom: 10px;
+}
+
+.popover-divider {
+  width: 100%;
+  height: 1px;
+  background-color: #008cba;
+  overflow: hidden;
+  margin-bottom: 10px;
+}
diff --git a/app/controllers/comments_controller.rb b/app/controllers/comments_controller.rb
index f6e4f7fb..01dcd9d5 100644
--- a/app/controllers/comments_controller.rb
+++ b/app/controllers/comments_controller.rb
@@ -19,6 +19,8 @@ class CommentsController < ApplicationController
       @comments = Comment.where(file_id: params[:file_id])
       @comments.map{|comment|
         comment.username = comment.user.displayname
+        comment.date = comment.created_at.strftime('%d.%m.%Y %k:%M')
+        comment.updated = (comment.created_at != comment.updated_at)
       }
     else
       @comments = []
diff --git a/app/controllers/request_for_comments_controller.rb b/app/controllers/request_for_comments_controller.rb
index eb2305cc..fca5c99b 100644
--- a/app/controllers/request_for_comments_controller.rb
+++ b/app/controllers/request_for_comments_controller.rb
@@ -11,14 +11,45 @@ class RequestForCommentsController < ApplicationController
   # GET /request_for_comments
   # GET /request_for_comments.json
   def index
-    @search = RequestForComment.last_per_user(2).search(params[:q])
+    @search = RequestForComment
+                  .last_per_user(2)
+                  .joins('join "submissions" s on s.id = request_for_comments.submission_id
+                          left outer join "files" f on f.context_id = s.id
+                          left outer join "comments" on comments.file_id = f.id')
+                  .group('request_for_comments.id, request_for_comments.user_id, request_for_comments.exercise_id,
+                          request_for_comments.file_id, request_for_comments.question, request_for_comments.created_at,
+                          request_for_comments.updated_at, request_for_comments.user_type, request_for_comments.solved,
+                          request_for_comments.submission_id, request_for_comments.row_number') # ugly, but rails wants it this way
+                  .select('request_for_comments.*, max(comments.updated_at) as last_comment')
+                  .search(params[:q])
     @request_for_comments = @search.result.order('created_at DESC').paginate(page: params[:page])
     authorize!
   end
 
   def get_my_comment_requests
-    @search = RequestForComment.where(user_id: current_user.id).order('created_at DESC').search(params[:q])
-    @request_for_comments = @search.result.paginate(page: params[:page])
+    @search = RequestForComment
+                  .where(user_id: current_user.id)
+                  .joins('join "submissions" s on s.id = request_for_comments.submission_id
+                          left outer join "files" f on f.context_id = s.id
+                          left outer join "comments" on comments.file_id = f.id')
+                  .group('request_for_comments.id')
+                  .select('request_for_comments.*, max(comments.updated_at) as last_comment')
+                  .search(params[:q])
+    @request_for_comments = @search.result.order('created_at DESC').paginate(page: params[:page])
+    render 'index'
+  end
+
+  def get_rfcs_with_my_comments
+    @search = RequestForComment
+                  .joins(:comments) # we don't need to outer join here, because we know the user has commented on these
+                  .where(comments: {user_id: current_user.id})
+                  .joins('join "submissions" s on s.id = request_for_comments.submission_id
+                          left outer join "files" f on f.context_id = s.id
+                          left outer join "comments" as c on c.file_id = f.id')
+                  .group('request_for_comments.id')
+                  .select('request_for_comments.*, max(c.updated_at) as last_comment')
+                  .search(params[:q])
+    @request_for_comments = @search.result.order('last_comment DESC').paginate(page: params[:page])
     render 'index'
   end
 
diff --git a/app/models/comment.rb b/app/models/comment.rb
index ceeb9c36..a5946ac9 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -1,7 +1,7 @@
 class Comment < ActiveRecord::Base
   # inherit the creation module: encapsulates that this is a polymorphic user, offers some aliases and makes sure that all necessary attributes are set.
   include Creation
-  attr_accessor :username
+  attr_accessor :username, :date, :updated
 
   belongs_to :file, class_name: 'CodeOcean::File'
   belongs_to :user, polymorphic: true
diff --git a/app/policies/comment_policy.rb b/app/policies/comment_policy.rb
index ef7a0922..549c8438 100644
--- a/app/policies/comment_policy.rb
+++ b/app/policies/comment_policy.rb
@@ -12,7 +12,7 @@ class CommentPolicy < ApplicationPolicy
     everyone
   end
 
-  [:new?, :destroy?].each do |action|
+  [:new?, :destroy?, :update?].each do |action|
     define_method(action) { admin? || author? }
   end
 
diff --git a/app/views/application/_session.html.slim b/app/views/application/_session.html.slim
index cbbf3b12..eb9f4d23 100644
--- a/app/views/application/_session.html.slim
+++ b/app/views/application/_session.html.slim
@@ -10,6 +10,7 @@
         li = link_to(t('internal_users.show.link'), current_user)
       li = link_to(t('request_for_comments.index.all'), request_for_comments_path)
       li = link_to(t('request_for_comments.index.get_my_comment_requests'), my_request_for_comments_path)
+      li = link_to(t('request_for_comments.index.get_my_rfc_activity'), my_rfc_activity_path)
       - if current_user.internal_user?
         li = link_to(t('sessions.destroy.link'), sign_out_path, method: :delete)
 - else
diff --git a/app/views/comments/index.json.jbuilder b/app/views/comments/index.json.jbuilder
index 85172014..55dfac49 100644
--- a/app/views/comments/index.json.jbuilder
+++ b/app/views/comments/index.json.jbuilder
@@ -1,4 +1,4 @@
 json.array!(@comments) do |comment|
-  json.extract! comment, :id, :user_id, :file_id, :row, :column, :text, :username
+  json.extract! comment, :id, :user_id, :file_id, :row, :column, :text, :username, :date, :updated
   json.url comment_url(comment, format: :json)
 end
diff --git a/app/views/request_for_comments/index.html.slim b/app/views/request_for_comments/index.html.slim
index db16b562..a081dd55 100644
--- a/app/views/request_for_comments/index.html.slim
+++ b/app/views/request_for_comments/index.html.slim
@@ -20,6 +20,7 @@ h1 = RequestForComment.model_name.human(count: 2)
           i class="fa fa-comment" aria-hidden="true" title = t('request_for_comments.comments') align="center"
         th = t('activerecord.attributes.request_for_comments.username')
         th = t('activerecord.attributes.request_for_comments.requested_at')
+        th = t('activerecord.attributes.request_for_comments.last_update')
     tbody
       - @request_for_comments.each do |request_for_comment|
         tr data-id=request_for_comment.id
@@ -36,5 +37,6 @@ h1 = RequestForComment.model_name.human(count: 2)
           td = request_for_comment.comments_count
           td = request_for_comment.user.displayname
           td = t('shared.time.before', time: distance_of_time_in_words_to_now(request_for_comment.created_at))
+          td = t('shared.time.before', time: distance_of_time_in_words_to_now(request_for_comment.last_comment.nil? ? request_for_comment.updated_at : request_for_comment.last_comment))
 
 = render('shared/pagination', collection: @request_for_comments)
\ No newline at end of file
diff --git a/app/views/request_for_comments/show.html.erb b/app/views/request_for_comments/show.html.erb
index b28c1eb9..ab60ef91 100644
--- a/app/views/request_for_comments/show.html.erb
+++ b/app/views/request_for_comments/show.html.erb
@@ -64,6 +64,8 @@
   </h5>
 </div>
 <hr>
+
+<div class="hidden sanitizer"></div>
 <!--
 do not put a carriage return in the line below. it will be present in the presentation of the source code, otherwise.
 also, all settings from the rails model needed for the editor configuration in the JavaScript are attached to the editor as data attributes here.
@@ -134,11 +136,24 @@ also, all settings from the rails model needed for the editor configuration in t
     currentEditor.setReadOnly(true);
     // set editor mode (used for syntax highlighting
     currentEditor.getSession().setMode($(editor).data('mode'));
+    currentEditor.getSession().setOption("useWorker", false);
 
     setAnnotations(currentEditor, $(editor).data('file-id'));
     currentEditor.on("guttermousedown", handleSidebarClick);
   });
 
+  function cleanupPopovers() {
+    // remove all possible popovers
+    $('.editor > .ace_gutter > .ace_gutter-layer > .ace_gutter-cell').popover('destroy');
+  }
+
+  function preprocess(commentText) {
+      // sanitize comments to deal with XSS attacks:
+      commentText = $('div.sanitizer').text(commentText).html();
+      // display original line breaks:
+      return commentText.replace(/\n/g, '<br>');
+  }
+
   function setAnnotations(editor, fileid) {
     var session = editor.getSession();
 
@@ -152,18 +167,65 @@ also, all settings from the rails model needed for the editor configuration in t
     });
 
     jqrequest.done(function(response){
-      $.each(response, function(index, comment) {
-        comment.className = "code-ocean_comment";
+      // comments need to be sorted to cluster them per line
+      var comments = response.slice().sort(function (a, b) {
+          return a.row - b.row;
+      });
+      while (comments.length > 0) {
+        // new cluster of comments
+        var cluster = [];
+        var clusterRow = comments[0].row;
+        // now collect all comments on this line
+        while (comments.length > 0 && comments[0].row === clusterRow) {
+          cluster.push(comments.shift());
+        }
+        // sort the comments by creation date
+        cluster = cluster.sort(function (a, b) {
+            return a.id - b.id;
+        });
 
+        // build the markup for the current line's popover
+        var popupContent = '';
+        cluster.forEach(function(comment, index) {
+            if (index !== 0) {
+                popupContent += '<div class="popover-divider"></div>'
+            }
+            popupContent += '<p class="comment">';
+            popupContent += '<div class="popover-header">' +
+                '<div class="popover-username">' + preprocess(comment.username) + '</div>' +
+                '<div class="popover-date">' + comment.date + '</div>';
+            if (comment.updated) {
+                popupContent += '<div class="popover-updated">' +
+                    '<i class="fa fa-pencil" aria-hidden="true"></i>' +
+                    '<%= t('request_for_comments.comment_edited') %>' +
+                    '</div>'
+            }
+            popupContent += '</div>';
+            popupContent += '<div class="popover-comment">' + preprocess(comment.text) + '</div>';
+            popupContent += '</p>';
+        });
+
+        // attach the popover to the ace sidebar (where the comment icon is displayed)
+        var icon = $('*[data-file-id="' + fileid + '"]')          // the editor for this file
+                .find('.ace_gutter > .ace_gutter-layer')          // the sidebar
+                .find('div:nth-child(' + (clusterRow + 1) + ')'); // the correct line
+        icon.popover({
+          content: popupContent,
+          html: true, // necessary to style comments. XSS is not possible due to comment pre-processing (sanitizing)
+          trigger: 'hover',
+          container: 'body'
+        });
+      }
+
+      $.each(response, function(index, comment) {
+        comment.className = 'code-ocean_comment';
         // if we have tabs or carriage returns in the comment, just add the name and leave it as it is. otherwise: format!
         if(comment.text.includes("\n") || comment.text.includes("\t")){
           comment.text = comment.username + ": " + comment.text;
         } else {
-          comment.text = comment.username + ": " + stringDivider(comment.text, 80, "\n\t\t");
+          comment.text = comment.username + ": " + stringDivider(comment.text, 80, "\n");
         }
-
       });
-
       session.setAnnotations(response);
     })
   }
@@ -181,6 +243,7 @@ also, all settings from the rails model needed for the editor configuration in t
   }
 
   function deleteComment(file_id, row, editor) {
+    cleanupPopovers();
     var jqxhr = $.ajax({
       type: 'DELETE',
       url: "/comments",
@@ -195,6 +258,7 @@ also, all settings from the rails model needed for the editor configuration in t
   }
 
   function createComment(file_id, row, editor, commenttext){
+    cleanupPopovers();
     var jqxhr = $.ajax({
       data: {
         comment: {
diff --git a/config/locales/de.yml b/config/locales/de.yml
index c2414a16..7b59dbc0 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -94,6 +94,7 @@ de:
         requested_at: Angefragezeitpunkt
         question: "Frage"
         close: "Fenster schließen"
+        last_update: "Letzte Aktivität"
       submission:
         cause: Anlass
         code: Code
@@ -460,7 +461,7 @@ de:
           Thank you for helping other users on CodeOcean!
           <br>
           This mail was automatically sent by CodeOcean. <br>
-        subject: "%{author} sagt danke!"
+        subject: "%{author} sagt Danke!"
   request_for_comments:
     click_here: Zum Kommentieren auf die Seitenleiste klicken!
     comments: Kommentare
@@ -472,6 +473,8 @@ de:
     index:
       get_my_comment_requests: Meine Kommentaranfragen
       all: "Alle Kommentaranfragen"
+      get_rfcs_with_my_comments: Kommentaranfragen die ich kommentiert habe
+      get_my_rfc_activity: "Meine Kommentaraktivität"
     no_question: "Der Autor hat keine Frage zu dieser Anfrage gestellt."
     mark_as_solved: "Diese Frage als beantwortet markieren"
     show_all: "Alle Anfragen anzeigen"
@@ -482,6 +485,7 @@ de:
     write_a_thank_you_node: "Wenn Sie möchten, können Sie sich bei allen Mitstudenten, die Ihnen bei der Beantwortung Ihrer Frage geholfen haben, bedanken:"
     send_thank_you_note: "Senden"
     cancel_thank_you_note: "Nichts senden"
+    comment_edited: "bearbeitet"
   sessions:
     create:
       failure: Fehlerhafte E-Mail oder Passwort.
diff --git a/config/locales/en.yml b/config/locales/en.yml
index d76774d2..102ef062 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -115,6 +115,7 @@ en:
         requested_at: Request Date
         question: "Question"
         close: Close window
+        last_update: "Last Update"
       submission:
         cause: Cause
         code: Code
@@ -493,6 +494,8 @@ en:
     index:
       all: All Requests for Comments
       get_my_comment_requests: My Requests for Comments
+      get_rfcs_with_my_comments: Requests for Comments I have commented on
+      get_my_rfc_activity: "My Comment Activity"
     no_question: "The author did not enter a question for this request."
     mark_as_solved: "Mark this question as answered"
     show_all: "All requests"
@@ -503,6 +506,7 @@ en:
     write_a_thank_you_node: "If you want, you can write a thank you note to all your commenters:"
     send_thank_you_note: "Send"
     cancel_thank_you_note: "Don't send"
+    comment_edited: "edited"
   sessions:
     create:
       failure: Invalid email or password.
diff --git a/config/routes.rb b/config/routes.rb
index 24a9671d..73d3ca08 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -27,6 +27,7 @@ Rails.application.routes.draw do
     end
   end
   get '/my_request_for_comments', as: 'my_request_for_comments', to: 'request_for_comments#get_my_comment_requests'
+  get '/my_rfc_activity', as: 'my_rfc_activity', to: 'request_for_comments#get_rfcs_with_my_comments'
 
   delete '/comment_by_id', to: 'comments#destroy_by_id'
   put '/comments', to: 'comments#update'