diff --git a/app/assets/javascripts/base.js b/app/assets/javascripts/base.js
index b7263d48..08e9afd1 100644
--- a/app/assets/javascripts/base.js
+++ b/app/assets/javascripts/base.js
@@ -11,7 +11,7 @@ window.CodeOcean = {
 var ANIMATION_DURATION = 500;
 
 $.isController = function(name) {
-  return $('.container[data-controller="' + name + '"]').isPresent();
+  return $('div[data-controller="' + name + '"]').isPresent();
 };
 
 $.fn.isPresent = function() {
diff --git a/app/assets/javascripts/editor/editor.js.erb b/app/assets/javascripts/editor/editor.js.erb
index c4cb46f9..33271a44 100644
--- a/app/assets/javascripts/editor/editor.js.erb
+++ b/app/assets/javascripts/editor/editor.js.erb
@@ -110,6 +110,10 @@ configureEditors: function () {
 
   // The event ready.jstree is fired too early and thus doesn't work.
   selectFileInJsTree: function(filetree, file_id) {
+    if (!filetree.is(':visible'))
+        // The left sidebar is not shown and thus the filetree is not rendered.
+        return;
+
     if (!filetree.hasClass('jstree-loading')) {
       filetree.jstree("deselect_all");
       filetree.jstree().select_node(file_id);
@@ -224,6 +228,11 @@ configureEditors: function () {
       // remove last (empty) that is there by default line
       document.removeLines(document.getLength() - 1, document.getLength() - 1);
       editor.setReadOnly($(element).data('read-only') !== undefined);
+      if (editor.getReadOnly()) {
+        editor.setHighlightActiveLine(false);
+        editor.setHighlightGutterLine(false);
+        editor.renderer.$cursorLayer.element.style.opacity = 0;
+      }
       editor.setShowPrintMargin(false);
       editor.setTheme(this.THEME);
 
@@ -458,7 +467,7 @@ configureEditors: function () {
 
     var editor = this.editor_for_file.get(file);
     editor.gotoLine(line, 0);
-
+    event.preventDefault();
   },
 
   augmentStacktraceInOutput: function () {
@@ -722,6 +731,7 @@ configureEditors: function () {
     this.initPrompt();
     this.renderScore();
     this.showFirstFile();
+    this.resizeAceEditors();
 
     $(window).on("beforeunload", this.unloadAutoSave.bind(this));
     // create autosave when the editor is opened the first time
diff --git a/app/assets/javascripts/editor/evaluation.js b/app/assets/javascripts/editor/evaluation.js
index 5e631b2b..6c90abd7 100644
--- a/app/assets/javascripts/editor/evaluation.js
+++ b/app/assets/javascripts/editor/evaluation.js
@@ -27,8 +27,11 @@ CodeOceanEditorEvaluation = {
   printScoringResult: function (result, index) {
     $('#results').show();
     var card = $('#dummies').children().first().clone();
-    this.populateCard(card, result, index);
-    $('#results ul').first().append(card);
+    if (card.isPresent()) {
+        // the card won't be present if @embed_options[:hide_test_results] == true
+        this.populateCard(card, result, index);
+        $('#results ul').first().append(card);
+    }
   },
 
   printScoringResults: function (response) {
@@ -141,14 +144,19 @@ CodeOceanEditorEvaluation = {
   },
 
   printOutput: function (output, colorize, index) {
+    if (output.stderr === undefined && output.stdout === undefined) {
+        // Prevent empty element with no text at all
+        return;
+    }
+
     var element = this.findOrCreateOutputElement(index);
     if (!colorize) {
-      if (output.stdout != undefined && output.stdout != '') {
+      if (output.stdout !== undefined && output.stdout !== '') {
         //element.append(output.stdout)
         element.text(element.text() + output.stdout)
       }
 
-      if (output.stderr != undefined && output.stderr != '') {
+      if (output.stderr !== undefined && output.stderr !== '') {
         //element.append('StdErr: ' + output.stderr);
         element.text('StdErr: ' + element.text() + output.stderr);
       }
diff --git a/app/assets/javascripts/editor/participantsupport.js.erb b/app/assets/javascripts/editor/participantsupport.js.erb
index 9a8e54f8..23e98009 100644
--- a/app/assets/javascripts/editor/participantsupport.js.erb
+++ b/app/assets/javascripts/editor/participantsupport.js.erb
@@ -172,8 +172,9 @@ CodeOceanEditorRequestForComments = {
     this.createSubmission($('#requestComments'), null, createRequestForComments.bind(this));
 
     $('#comment-modal').modal('hide');
+    $('#question').val('');
     // we disabled the button to prevent that the user spams RFCs, but decided against this now.
     //var button = $('#requestComments');
     //button.prop('disabled', true);
-  },
+  }
 };
diff --git a/app/assets/javascripts/editor/submissions.js b/app/assets/javascripts/editor/submissions.js
index f55bdbb5..20911535 100644
--- a/app/assets/javascripts/editor/submissions.js
+++ b/app/assets/javascripts/editor/submissions.js
@@ -10,6 +10,7 @@ CodeOceanEditorSubmissions = {
    */
   createSubmission: function (initiator, filter, callback) {
     this.showSpinner(initiator);
+    var url = $(initiator).data('url') || $('#editor').data('submissions-url');
     var jqxhr = this.ajax({
       data: {
         submission: {
@@ -21,7 +22,7 @@ CodeOceanEditorSubmissions = {
       },
       dataType: 'json',
       method: 'POST',
-      url: $(initiator).data('url') || $('#editor').data('submissions-url')
+      url: url + '.json'
     });
     jqxhr.always(this.hideSpinner.bind(this));
     jqxhr.done(this.createSubmissionCallback.bind(this));
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index c58303ba..2fcece66 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -5,7 +5,7 @@ class ApplicationController < ActionController::Base
   MEMBER_ACTIONS = [:destroy, :edit, :show, :update]
 
   after_action :verify_authorized, except: [:help, :welcome]
-  before_action :set_locale, :allow_iframe_requests
+  before_action :set_locale, :allow_iframe_requests, :load_embed_options
   protect_from_forgery(with: :exception, prepend: true)
   rescue_from Pundit::NotAuthorizedError, with: :render_not_authorized
 
@@ -38,4 +38,14 @@ class ApplicationController < ActionController::Base
   def allow_iframe_requests
     response.headers.delete('X-Frame-Options')
   end
+
+  def load_embed_options
+    if session[:embed_options].present? && session[:embed_options].is_a?(Hash)
+      @embed_options = session[:embed_options].symbolize_keys
+    else
+      @embed_options = {}
+    end
+    @embed_options
+  end
+  private :load_embed_options
 end
diff --git a/app/controllers/concerns/lti.rb b/app/controllers/concerns/lti.rb
index 155e8895..3a0e5394 100644
--- a/app/controllers/concerns/lti.rb
+++ b/app/controllers/concerns/lti.rb
@@ -22,6 +22,7 @@ module Lti
     if (exercise_id.nil?)
       session.delete(:consumer_id)
       session.delete(:external_user_id)
+      session.delete(:embed_options)
     else
       LtiParameter.where(consumers_id: consumer_id,
                          external_users_id: user_id,
@@ -138,6 +139,7 @@ module Lti
   end
   private :set_current_user
 
+
   def set_study_group_membership
     return if mooc_course
     group = StudyGroup.find_or_create_by(external_id: @provider.resource_link_id, consumer: @consumer)
@@ -145,6 +147,26 @@ module Lti
     group.save
   end
 
+  def set_embedding_options
+    @embed_options = {}
+    [:hide_navbar,
+     :hide_exercise_description,
+     :disable_run,
+     :disable_score,
+     :disable_rfc,
+     :disable_interventions,
+     :hide_sidebar,
+     :read_only,
+     :hide_test_results,
+     :disable_hints].each do |option|
+      value = params["custom_embed_options_#{option}".to_sym] == 'true'
+      # Optimize storage and save only those that are true, the session cookie is limited to 4KB
+      @embed_options[option] = value if value.present?
+    end
+    session[:embed_options] = @embed_options
+  end
+  private :set_embedding_options
+
   def store_lti_session_data(options = {})
     lti_parameters = LtiParameter.find_or_create_by(consumers_id: options[:consumer].id,
                                                     external_users_id: @current_user.id,
diff --git a/app/controllers/concerns/submission_scoring.rb b/app/controllers/concerns/submission_scoring.rb
index 06bba11c..7436ac51 100644
--- a/app/controllers/concerns/submission_scoring.rb
+++ b/app/controllers/concerns/submission_scoring.rb
@@ -55,6 +55,11 @@ module SubmissionScoring
         }
       end
     end
+    if @embed_options.present? && @embed_options[:hide_test_results] && outputs.present?
+      outputs.each do |output|
+        output.except!(:error_messages, :count, :failed, :filename, :message, :passed, :stderr, :stdout)
+      end
+    end
     outputs
   end
 end
diff --git a/app/controllers/exercises_controller.rb b/app/controllers/exercises_controller.rb
index 839aef4c..79a669cf 100644
--- a/app/controllers/exercises_controller.rb
+++ b/app/controllers/exercises_controller.rb
@@ -188,7 +188,15 @@ class ExercisesController < ApplicationController
     user_got_intervention_in_exercise = UserExerciseIntervention.where(user: current_user, exercise: @exercise).size >= max_intervention_count_per_exercise
     user_got_enough_interventions = count_interventions_today >= max_intervention_count_per_day or user_got_intervention_in_exercise
 
-    @show_rfc_interventions = (not user_solved_exercise and not user_got_enough_interventions).to_s
+    unless @embed_options[:disable_interventions]
+      @show_rfc_interventions = (not user_solved_exercise and not user_got_enough_interventions).to_s
+      @show_break_interventions = false
+    else
+      @show_rfc_interventions = false
+      @show_break_interventions = false
+    end
+
+    @hide_rfc_button = @embed_options[:disable_rfc]
 
 
     @search = Search.new
diff --git a/app/controllers/flowr_controller.rb b/app/controllers/flowr_controller.rb
index e9f742b7..310d91d2 100644
--- a/app/controllers/flowr_controller.rb
+++ b/app/controllers/flowr_controller.rb
@@ -8,7 +8,7 @@ class FlowrController < ApplicationController
                      .order('testruns.created_at DESC').first
 
     # Return if no submission was found
-    if submission.blank?
+    if submission.blank? || @embed_options[:disable_hints] || @embed_options[:hide_test_results]
       skip_authorization
       render json: [], status: :ok
       return
diff --git a/app/controllers/proxy_exercises_controller.rb b/app/controllers/proxy_exercises_controller.rb
index 40bd20ca..2f3534d8 100644
--- a/app/controllers/proxy_exercises_controller.rb
+++ b/app/controllers/proxy_exercises_controller.rb
@@ -9,7 +9,7 @@ class ProxyExercisesController < ApplicationController
   private :authorize!
 
   def clone
-    proxy_exercise = @proxy_exercise.duplicate(token: nil, exercises: @proxy_exercise.exercises)
+    proxy_exercise = @proxy_exercise.duplicate(public: false, token: nil, exercises: @proxy_exercise.exercises, user: current_user)
     proxy_exercise.send(:generate_token)
     if proxy_exercise.save
       redirect_to(proxy_exercise, notice: t('shared.object_cloned', model:  ProxyExercise.model_name.human))
@@ -39,7 +39,7 @@ class ProxyExercisesController < ApplicationController
   end
 
   def proxy_exercise_params
-    params[:proxy_exercise].permit(:description, :title, :exercise_ids  => []) if params[:proxy_exercise].present?
+    params[:proxy_exercise].permit(:description, :title, :public, :exercise_ids  => []).merge(user_id: current_user.id, user_type: current_user.class.name) if params[:proxy_exercise].present?
   end
   private :proxy_exercise_params
 
diff --git a/app/controllers/request_for_comments_controller.rb b/app/controllers/request_for_comments_controller.rb
index 29c5a6ea..39f1ebb8 100644
--- a/app/controllers/request_for_comments_controller.rb
+++ b/app/controllers/request_for_comments_controller.rb
@@ -96,6 +96,10 @@ class RequestForCommentsController < ApplicationController
   # POST /request_for_comments
   # POST /request_for_comments.json
   def create
+    # Consider all requests as JSON
+    request.format = 'json'
+    raise Pundit::NotAuthorizedError if @embed_options[:disable_rfc]
+
     @request_for_comment = RequestForComment.new(request_for_comment_params)
     respond_to do |format|
       if @request_for_comment.save
diff --git a/app/controllers/sessions_controller.rb b/app/controllers/sessions_controller.rb
index 24b2e6b1..8d7760fc 100644
--- a/app/controllers/sessions_controller.rb
+++ b/app/controllers/sessions_controller.rb
@@ -1,7 +1,7 @@
 class SessionsController < ApplicationController
   include Lti
 
-  [:require_oauth_parameters, :require_valid_consumer_key, :require_valid_oauth_signature, :require_unique_oauth_nonce, :set_current_user, :set_study_group_membership, :require_valid_exercise_token].each do |method_name|
+  [:require_oauth_parameters, :require_valid_consumer_key, :require_valid_oauth_signature, :require_unique_oauth_nonce, :set_current_user, :require_valid_exercise_token, :set_study_group_membership, :set_embedding_options].each do |method_name|
     before_action(method_name, only: :create_through_lti)
   end
 
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 039efa02..bc3ec4a6 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -122,13 +122,18 @@ class SubmissionsController < ApplicationController
   def run
     # TODO reimplement SSEs with websocket commands
     # with_server_sent_events do |server_sent_event|
-    #   output = @docker_client.execute_run_command(@submission, params[:filename])
+    #   output = @docker_client.execute_run_command(@submission, sanitize_filename)
 
     #   server_sent_event.write({stdout: output[:stdout]}, event: 'output') if output[:stdout]
     #   server_sent_event.write({stderr: output[:stderr]}, event: 'output') if output[:stderr]
     # end
 
     hijack do |tubesock|
+      if @embed_options[:disable_run]
+        kill_socket(tubesock)
+        return
+      end
+
       # probably add:
       # ensure
       #   #guarantee that the thread is releasing the DB connection after it is done
@@ -142,7 +147,7 @@ class SubmissionsController < ApplicationController
       # give the docker_client the tubesock object, so that it can send messages (timeout)
       @docker_client.tubesock = tubesock
 
-      result = @docker_client.execute_run_command(@submission, params[:filename])
+      result = @docker_client.execute_run_command(@submission, sanitize_filename)
       tubesock.send_data JSON.dump({'cmd' => 'status', 'status' => result[:status]})
 
       if result[:status] == :container_running
@@ -195,6 +200,10 @@ class SubmissionsController < ApplicationController
     # save the output of this "run" as a "testrun" (scoring runs are saved in submission_scoring.rb)
     save_run_output
 
+    if @run_output.blank?
+      parse_message t('exercises.implement.no_output', timestamp: l(Time.now, format: :short)), 'stdout', tubesock
+    end
+
     # Hijacked connection needs to be notified correctly
     tubesock.send_data JSON.dump({'cmd' => 'exit'})
     tubesock.close
@@ -214,8 +223,8 @@ class SubmissionsController < ApplicationController
       @run_output = 'timeout: ' + @run_output # add information that this run timed out to the buffer
     else
       # Filter out information about run_command, test_command, user or working directory
-      run_command = @submission.execution_environment.run_command % command_substitutions(params[:filename])
-      test_command = @submission.execution_environment.test_command % command_substitutions(params[:filename])
+      run_command = @submission.execution_environment.run_command % command_substitutions(sanitize_filename)
+      test_command = @submission.execution_environment.test_command % command_substitutions(sanitize_filename)
       unless /root|workspace|#{run_command}|#{test_command}/.match(message)
         parse_message(message, 'stdout', tubesock)
       end
@@ -291,6 +300,11 @@ class SubmissionsController < ApplicationController
 
   def score
     hijack do |tubesock|
+      if @embed_options[:disable_score]
+        kill_socket(tubesock)
+        return
+      end
+
       Thread.new { EventMachine.run } unless EventMachine.reactor_running? && EventMachine.reactor_thread.alive?
       # tubesock is the socket to the client
 
@@ -308,6 +322,7 @@ class SubmissionsController < ApplicationController
   end
 
   def send_hints(tubesock, errors)
+    return if @embed_options[:disable_hints]
     errors = errors.to_a.uniq { |e| e.hint}
     errors.each do | error |
       tubesock.send_data JSON.dump({cmd: 'hint', hint: error.hint, description: error.error_template.description})
@@ -320,7 +335,7 @@ class SubmissionsController < ApplicationController
   private :set_docker_client
 
   def set_file
-    @file = @files.detect { |file| file.name_with_extension == params[:filename] }
+    @file = @files.detect { |file| file.name_with_extension == sanitize_filename }
     head :not_found unless @file
   end
   private :set_file
@@ -361,7 +376,7 @@ class SubmissionsController < ApplicationController
     hijack do |tubesock|
       Thread.new { EventMachine.run } unless EventMachine.reactor_running? && EventMachine.reactor_thread.alive?
 
-      output = @docker_client.execute_test_command(@submission, params[:filename])
+      output = @docker_client.execute_test_command(@submission, sanitize_filename)
 
       # tubesock is the socket to the client
       tubesock.send_data JSON.dump(output)
@@ -405,4 +420,8 @@ class SubmissionsController < ApplicationController
     end
     path
   end
+
+  def sanitize_filename
+    params[:filename].gsub(/\.json$/, '')
+  end
 end
diff --git a/app/mailers/user_mailer.rb b/app/mailers/user_mailer.rb
index 497c2a31..b7b3d52f 100644
--- a/app/mailers/user_mailer.rb
+++ b/app/mailers/user_mailer.rb
@@ -1,4 +1,10 @@
 class UserMailer < ActionMailer::Base
+
+  def mail(*args)
+    # used to prevent the delivery to pseudonymous users without a valid email address
+    super unless args.first[:to].blank?
+  end
+
   def activation_needed_email(user)
     @activation_url = activate_internal_user_url(user, token: user.activation_token)
     mail(subject: t('mailers.user_mailer.activation_needed.subject'), to: user.email)
diff --git a/app/models/external_user.rb b/app/models/external_user.rb
index 053d3795..e19a269e 100644
--- a/app/models/external_user.rb
+++ b/app/models/external_user.rb
@@ -10,5 +10,4 @@ class ExternalUser < User
       name
     end
   end
-
 end
diff --git a/app/models/proxy_exercise.rb b/app/models/proxy_exercise.rb
index 328fffa6..bb17b30a 100644
--- a/app/models/proxy_exercise.rb
+++ b/app/models/proxy_exercise.rb
@@ -1,11 +1,16 @@
 class ProxyExercise < ApplicationRecord
+    include Creation
+    include DefaultValues
 
     after_initialize :generate_token
     after_initialize :set_reason
+    after_initialize :set_default_values
 
     has_and_belongs_to_many :exercises
     has_many :user_proxy_exercise_exercises
 
+    validates :public, boolean_presence: true
+
     def count_files
         exercises.count
     end
@@ -19,6 +24,11 @@ class ProxyExercise < ApplicationRecord
     end
     private :generate_token
 
+    def set_default_values
+      set_default_values_if_present(public: false)
+    end
+    private :set_default_values
+
     def duplicate(attributes = {})
       proxy_exercise = dup
       proxy_exercise.attributes = attributes
diff --git a/app/views/application/_breadcrumbs.html.slim b/app/views/application/_breadcrumbs.html.slim
index 7899ae0e..570f5624 100644
--- a/app/views/application/_breadcrumbs.html.slim
+++ b/app/views/application/_breadcrumbs.html.slim
@@ -1,19 +1,20 @@
 - if current_user.try(:internal_user?)
-  ul.breadcrumb
-    - if model = Kernel.const_get(controller_path.classify) rescue nil
-      - object = model.find_by(id: params[:id])
-      - if model.try(:nested_resource?)
-        li.breadcrumb-item = model.model_name.human(count: 2)
-        - if object
-          li.breadcrumb-item = object
-      - else
-        li.breadcrumb-item = link_to(model.model_name.human(count: 2), send(:"#{model.model_name.collection}_path"))
-        - if object
-          li.breadcrumb-item = link_to(object, send(:"#{model.model_name.singular}_path", object))
-      li.breadcrumb-item.active
-        - if I18n.translation_present?("shared.#{params[:action]}")
-          = t("shared.#{params[:action]}")
+  .container
+    ul.breadcrumb
+      - if model = Kernel.const_get(controller_path.classify) rescue nil
+        - object = model.find_by(id: params[:id])
+        - if model.try(:nested_resource?)
+          li.breadcrumb-item = model.model_name.human(count: 2)
+          - if object
+            li.breadcrumb-item = object
         - else
-          = t("#{controller_name}.index.#{params[:action]}")
-    - else
-      li.breadcrumb-item.active = t("breadcrumbs.#{controller_name}.#{params[:action]}")
+          li.breadcrumb-item = link_to(model.model_name.human(count: 2), send(:"#{model.model_name.collection}_path"))
+          - if object
+            li.breadcrumb-item = link_to(object, send(:"#{model.model_name.singular}_path", object))
+        li.breadcrumb-item.active
+          - if I18n.translation_present?("shared.#{params[:action]}")
+            = t("shared.#{params[:action]}")
+          - else
+            = t("#{controller_name}.index.#{params[:action]}")
+      - else
+        li.breadcrumb-item.active = t("breadcrumbs.#{controller_name}.#{params[:action]}")
diff --git a/app/views/application/_flash.html.slim b/app/views/application/_flash.html.slim
index 4a78c032..4675a913 100644
--- a/app/views/application/_flash.html.slim
+++ b/app/views/application/_flash.html.slim
@@ -1,4 +1,4 @@
-#flash-container
+#flash-container.container
   #flash.container.fixed_error_messages data-message-failure=t('shared.message_failure')
     - %w[alert danger info notice success warning].each do |severity|
       div.alert.flash class="alert-#{{'alert' => 'warning', 'notice' => 'success'}.fetch(severity, severity)} alert-dismissible fade show"
diff --git a/app/views/application/welcome.html.slim b/app/views/application/welcome.html.slim
index 8f9448c7..84692ec1 100644
--- a/app/views/application/welcome.html.slim
+++ b/app/views/application/welcome.html.slim
@@ -3,6 +3,6 @@ h1 = t('.title', application_name: application_name)
 - if current_user.try(:external_user?)
   p = t('.text_signed_in_as_external_user', application_name: application_name)
 - elsif current_user.try(:internal_user?)
-  p = t('.text_signed_in_as_internal_user', user_name: current_user.name)
+  p = t('.text_signed_in_as_internal_user', user_name: current_user.displayname)
 - else
   p == t('.text_signed_out', application_name: application_name, sign_in_path: sign_in_path)
diff --git a/app/views/execution_environments/shell.html.slim b/app/views/execution_environments/shell.html.slim
index 5b499a35..ae35c7b8 100644
--- a/app/views/execution_environments/shell.html.slim
+++ b/app/views/execution_environments/shell.html.slim
@@ -4,5 +4,5 @@ h1 = @execution_environment
   .form-group
     label for='command' = t('.command')
     input#command.form-control type='text'
-  pre#output data-message-no-output=t('exercises.implement.no_output')
+  pre#output data-message-no-output=t('exercises.implement.no_output', timestamp: l(Time.now, format: :short))
     p = t('exercises.implement.no_output_yet')
diff --git a/app/views/exercise_collections/show.html.slim b/app/views/exercise_collections/show.html.slim
index 4fa6a8ac..db0945f3 100644
--- a/app/views/exercise_collections/show.html.slim
+++ b/app/views/exercise_collections/show.html.slim
@@ -3,7 +3,7 @@ h1
   = render('shared/edit_button', object: @exercise_collection)
 
 = row(label: 'exercise_collections.name', value: @exercise_collection.name)
-= row(label: 'exercise_collections.user', value: link_to(@exercise_collection.user.name, @exercise_collection.user)) unless @exercise_collection.user.nil?
+= row(label: 'exercise_collections.user', value: link_to(@exercise_collection.user.displayname, @exercise_collection.user)) unless @exercise_collection.user.nil?
 = row(label: 'exercise_collections.use_anomaly_detection', value: @exercise_collection.use_anomaly_detection)
 = row(label: 'exercise_collections.updated_at', value: @exercise_collection.updated_at)
 
@@ -24,5 +24,5 @@ h4.mt-4 = t('activerecord.attributes.exercise_collections.exercises')
           td = exercise_collection_item.position
           td = link_to(exercise.title, exercise)
           td = link_to_if(exercise.execution_environment && policy(exercise.execution_environment).show?, exercise.execution_environment, exercise.execution_environment)
-          td = link_to_if(exercise.user && policy(exercise.user).show?, exercise.user.name, exercise.user)
+          td = link_to_if(exercise.user && policy(exercise.user).show?, exercise.user.displayname, exercise.user)
           td = link_to(t('shared.statistics'), statistics_exercise_path(exercise), 'data-turbolinks' => "false")
diff --git a/app/views/exercises/_editor.html.slim b/app/views/exercises/_editor.html.slim
index 700a9855..7323f21e 100644
--- a/app/views/exercises/_editor.html.slim
+++ b/app/views/exercises/_editor.html.slim
@@ -5,26 +5,29 @@
 - show_rfc_interventions = @show_rfc_interventions || "false"
 - hide_rfc_button = @hide_rfc_button || false
 #editor.row data-exercise-id=@exercise.id data-message-depleted=t('exercises.editor.depleted') data-message-timeout=t('exercises.editor.timeout',  permitted_execution_time: @exercise.execution_environment.permitted_execution_time) data-submissions-url=submissions_path data-user-id=@current_user.id data-user-external-id=external_user_external_id data-working-times-url=working_times_exercise_path(@exercise) data-intervention-save-url=intervention_exercise_path(@exercise) data-rfc-interventions=show_rfc_interventions data-break-interventions=show_break_interventions data-course_token=@course_token data-search-save-url=search_exercise_path(@exercise)
-  div id="sidebar" class=(@exercise.hide_file_tree ? 'sidebar-col-collapsed' : 'sidebar-col') = render('editor_file_tree', exercise: @exercise, files: @files)
+  - unless @embed_options[:hide_sidebar]
+    div id="sidebar" class=(@exercise.hide_file_tree ? 'sidebar-col-collapsed' : 'sidebar-col') = render('editor_file_tree', exercise: @exercise, files: @files)
   div.editor-col.col.p-0 id='frames'
     #editor-buttons.btn-group.enforce-bottom-margin
       = render('editor_button', disabled: true, icon: 'fa fa-ban', id: 'dummy', label: t('exercises.editor.dummy'))
-      = render('editor_button', icon: 'fa fa-desktop', id: 'render', label: t('exercises.editor.render'))
-      = render('editor_button', data: {:'data-message-failure' => t('exercises.editor.run_failure'), :'data-message-network' => t('exercises.editor.network'), :'data-message-success' => t('exercises.editor.run_success'), :'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-play', id: 'run', label: t('exercises.editor.run'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + r'))
-      = render('editor_button', data: {:'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-stop', id: 'stop', label: t('exercises.editor.stop'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + r'))
-      = render('editor_button', data: {:'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-rocket', id: 'test', label: t('exercises.editor.test'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + t'))
-      = render('editor_button', data: {:'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-trophy', id: 'assess', label: t('exercises.editor.score'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + s'))
+      = render('editor_button', icon: 'fa fa-desktop', id: 'render', label: t('exercises.editor.render')) unless @embed_options[:hide_run_button]
+      = render('editor_button', data: {:'data-message-failure' => t('exercises.editor.run_failure'), :'data-message-network' => t('exercises.editor.network'), :'data-message-success' => t('exercises.editor.run_success'), :'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-play', id: 'run', label: t('exercises.editor.run'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + r')) unless @embed_options[:disable_run]
+      = render('editor_button', data: {:'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-stop', id: 'stop', label: t('exercises.editor.stop'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + r')) unless @embed_options[:disable_run]
+      = render('editor_button', data: {:'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-rocket', id: 'test', label: t('exercises.editor.test'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + t')) unless @embed_options[:disable_run]
+      = render('editor_button', data: {:'data-placement' => 'top', :'data-toggle' => 'tooltip', :'data-container' => 'body'}, icon: 'fa fa-trophy', id: 'assess', label: t('exercises.editor.score'), title: t('shared.tooltips.shortcut', shortcut: 'ALT + s')) unless @embed_options[:disable_score]
       // todo: check this
-      - if not hide_rfc_button
+      - unless hide_rfc_button
         = render('editor_button', icon: 'fa fa-comment', id: 'requestComments', label: t('exercises.editor.requestComments'), title: t('exercises.editor.requestCommentsTooltip'))
     - @files.each do |file|
+      - file.read_only = true if @embed_options[:read_only]
       = render('editor_frame', exercise: exercise, file: file)
     #autosave-label
       = t('exercises.editor.lastsaved')
       span
       button style="display:none" id="autosave"
-  div id='output_sidebar' class='output-col-collapsed' = render('exercises/editor_output', external_user_id: external_user_id, consumer_id: consumer_id )
+  - unless @embed_options[:disable_run] && @embed_options[:disable_score]
+    div id='output_sidebar' class='output-col-collapsed' = render('exercises/editor_output', external_user_id: external_user_id, consumer_id: consumer_id )
 
 
-= render('shared/modal', id: 'comment-modal', title: t('exercises.implement.comment.request'), template: 'exercises/_request_comment_dialogcontent')
-= render('shared/modal', id: 'break-intervention-modal', title: t('exercises.implement.break_intervention.title'), template: 'interventions/_break_intervention_modal')
+= render('shared/modal', id: 'comment-modal', title: t('exercises.implement.comment.request'), template: 'exercises/_request_comment_dialogcontent') unless @embed_options[:disable_rfc]
+= render('shared/modal', id: 'break-intervention-modal', title: t('exercises.implement.break_intervention.title'), template: 'interventions/_break_intervention_modal') unless @embed_options[:disable_interventions]
diff --git a/app/views/exercises/_editor_output.html.slim b/app/views/exercises/_editor_output.html.slim
index dd6849da..7948e548 100644
--- a/app/views/exercises/_editor_output.html.slim
+++ b/app/views/exercises/_editor_output.html.slim
@@ -1,6 +1,6 @@
 div id='output_sidebar_collapsed'
   = render('editor_button', classes: 'btn-block btn-primary btn', data: {:'data-toggle' => 'tooltip', :'data-placement' => 'left'}, title: t('exercises.editor.expand_output_sidebar'), icon: 'fa fa-plus-square', id: 'toggle-sidebar-output-collapsed', label: '')
-div.h-100 id='output_sidebar_uncollapsed' class='d-none col-sm-12 enforce-bottom-margin' data-message-no-output=t('exercises.implement.no_output')
+div.h-100 id='output_sidebar_uncollapsed' class='d-none col-sm-12 enforce-bottom-margin' data-message-no-output=t('exercises.implement.no_output_yet')
   .row
     = render('editor_button', classes: 'btn-block btn-primary btn', icon: 'fa fa-minus-square', id: 'toggle-sidebar-output', label: t('exercises.editor.collapse_output_sidebar'))
 
@@ -10,17 +10,18 @@ div.h-100 id='output_sidebar_uncollapsed' class='d-none col-sm-12 enforce-bottom
         #results
           h2 = t('exercises.implement.results')
           p.test-count == t('exercises.implement.test_count', count: 0)
-          ul.list-unstyled
-          ul#dummies.d-none.list-unstyled
-            li.card.mt-2
-              .card-header.py-2
-                h5.card-title.m-0 == t('exercises.implement.file', filename: '', number: 0)
-              .card-body.bg-white.text-dark
-                = row(label: 'exercises.implement.passed_tests', value: t('shared.out_of', maximum_value: 0, value: 0).html_safe)
-                = row(label: 'activerecord.attributes.submission.score', value: t('shared.out_of', maximum_value: 0, value: 0).html_safe)
-                = row(label: 'exercises.implement.feedback')
-                = row(label: 'exercises.implement.error_messages')
-                /= row(label: 'exercises.implement.output', value: link_to(t('shared.show'), '#'))
+          - unless @embed_options[:hide_test_results]
+            ul.list-unstyled
+            ul#dummies.d-none.list-unstyled
+              li.card.mt-2
+                .card-header.py-2
+                  h5.card-title.m-0 == t('exercises.implement.file', filename: '', number: 0)
+                .card-body.bg-white.text-dark
+                  = row(label: 'exercises.implement.passed_tests', value: t('shared.out_of', maximum_value: 0, value: 0).html_safe)
+                  = row(label: 'activerecord.attributes.submission.score', value: t('shared.out_of', maximum_value: 0, value: 0).html_safe)
+                  = row(label: 'exercises.implement.feedback')
+                  = row(label: 'exercises.implement.error_messages')
+                  /= row(label: 'exercises.implement.output', value: link_to(t('shared.show'), '#'))
         #score data-maximum-score=@exercise.maximum_score data-score=@submission.try(:score)
           h4
             span == "#{t('activerecord.attributes.submission.score')}:&nbsp;"
@@ -44,12 +45,13 @@ div.h-100 id='output_sidebar_uncollapsed' class='d-none col-sm-12 enforce-bottom
           input#prompt-input.form-control type='text'
           span.input-group-btn
             button#prompt-submit.btn.btn-primary type="button" = t('exercises.editor.send')
-        #error-hints
-          .heading = t('exercises.implement.error_hints.heading')
-          ul.body
+        - unless @embed_options[:disable_hints]
+          #error-hints
+            .heading = t('exercises.implement.error_hints.heading')
+            ul.body
         #output.mt-2
           pre = t('exercises.implement.no_output_yet')
-        - if CodeOcean::Config.new(:code_ocean).read[:flowr][:enabled]
+        - if CodeOcean::Config.new(:code_ocean).read[:flowr][:enabled] && !@embed_options[:disable_hints] && !@embed_options[:hide_test_results]
           #flowrHint.card.text-white.bg-info data-url=CodeOcean::Config.new(:code_ocean).read[:flowr][:url] role='tab'
             .card-header = t('exercises.implement.flowr.heading')
             .card-body.text-dark.bg-white
diff --git a/app/views/exercises/feedback.html.slim b/app/views/exercises/feedback.html.slim
index 5090d0e2..26180cfd 100644
--- a/app/views/exercises/feedback.html.slim
+++ b/app/views/exercises/feedback.html.slim
@@ -13,7 +13,7 @@ h1 = link_to(@exercise, exercise_path(@exercise))
       li.card.mt-2
         .card-header role="tab" id="heading"
           div.clearfix.feedback-header
-            span.username = link_to(feedback.user.name, statistics_external_user_exercise_path(id: @exercise.id, external_user_id: feedback.user.id))
+            span.username = link_to(feedback.user.displayname, statistics_external_user_exercise_path(id: @exercise.id, external_user_id: feedback.user.id))
             - if feedback.anomaly_notification
               i class="fa fa-envelope-o" data-placement="top" data-toggle="tooltip" data-container="body" title=feedback.anomaly_notification.reason
             span.date = feedback.created_at
diff --git a/app/views/exercises/implement.html.slim b/app/views/exercises/implement.html.slim
index 1e872cbf..96f4ff74 100644
--- a/app/views/exercises/implement.html.slim
+++ b/app/views/exercises/implement.html.slim
@@ -1,17 +1,18 @@
 .row
   #editor-column.col-md-12
-    .exercise.clearfix
-      div
-        span.badge.badge-pill.badge-primary.float-right.score
+    - unless @embed_options[:hide_exercise_description]
+      .exercise.clearfix
+        div
+          span.badge.badge-pill.badge-primary.float-right.score
 
-        h1 id="exercise-headline"
-          i class="fa fa-chevron-down" id="description-symbol"
-          = @exercise.title
+          h1 id="exercise-headline"
+            i class="fa fa-chevron-down" id="description-symbol"
+            = @exercise.title
 
-      #description-card.lead.description-card
-        = render_markdown(@exercise.description)
+        #description-card.lead.description-card
+          = render_markdown(@exercise.description)
 
-      a#toggle href="#" data-show=t('shared.show') data-hide=t('shared.hide') = t('shared.hide')
+        a#toggle href="#" data-show=t('shared.show') data-hide=t('shared.hide') = t('shared.hide')
 
     #alert.alert.alert-danger role='alert'
       h4 = t('.alert.title')
diff --git a/app/views/external_users/index.html.slim b/app/views/external_users/index.html.slim
index 34359b2a..bff2509f 100644
--- a/app/views/external_users/index.html.slim
+++ b/app/views/external_users/index.html.slim
@@ -10,7 +10,7 @@ h1 = ExternalUser.model_name.human(count: 2)
     tbody
       - @users.each do |user|
         tr
-          td = user.name
+          td = user.displayname
           td = link_to(user.consumer, user.consumer)
           td = link_to(t('shared.show'), user)
 
diff --git a/app/views/external_users/show.html.slim b/app/views/external_users/show.html.slim
index 33e2dd6b..e5aee19e 100644
--- a/app/views/external_users/show.html.slim
+++ b/app/views/external_users/show.html.slim
@@ -1,4 +1,4 @@
-h1 = @user.name
+h1 = @user.displayname
 
 = row(label: 'external_user.name', value: @user.name)
 //= row(label: 'external_user.email', value: @user.email)
diff --git a/app/views/layouts/application.html.slim b/app/views/layouts/application.html.slim
index 64b5549f..cdc3eb4e 100644
--- a/app/views/layouts/application.html.slim
+++ b/app/views/layouts/application.html.slim
@@ -13,22 +13,23 @@ html lang='en'
     = yield(:head)
     = csrf_meta_tags
   body
-    nav.navbar.navbar-dark.bg-dark.navbar-expand-md.mb-4.py-1 role='navigation'
-      .container
-        .navbar-brand
-          i.fa.fa-code
-          = application_name
-        button.navbar-toggler data-target='#navbar-collapse' data-toggle='collapse' type='button' aria-expanded='false' aria-label='Toggle navigation'
-          span.navbar-toggler-icon
-        #navbar-collapse.collapse.navbar-collapse
-          = render('navigation', cached: true)
-          ul.nav.navbar-nav.ml-auto
-            = render('locale_selector', cached: true)
-            li.nav-item.mr-3 = link_to(t('shared.help.link'), '#modal-help', data: {toggle: 'modal'}, class: 'nav-link')
-            = render('session')
-    .container data-controller=controller_name
+    - unless @embed_options[:hide_navbar]
+      nav.navbar.navbar-dark.bg-dark.navbar-expand-md.mb-4.py-1 role='navigation'
+        .container
+          .navbar-brand
+            i.fa.fa-code
+            = application_name
+          button.navbar-toggler data-target='#navbar-collapse' data-toggle='collapse' type='button' aria-expanded='false' aria-label='Toggle navigation'
+            span.navbar-toggler-icon
+          #navbar-collapse.collapse.navbar-collapse
+            = render('navigation', cached: true)
+            ul.nav.navbar-nav.ml-auto
+              = render('locale_selector', cached: true)
+              li.nav-item.mr-3 = link_to(t('shared.help.link'), '#modal-help', data: {toggle: 'modal'}, class: 'nav-link')
+              = render('session')
+    div data-controller=controller_name
       = render('flash')
-      = render('breadcrumbs') if current_user.try(:internal_user?)
+      = render('breadcrumbs') if current_user.try(:internal_user?) && !@embed_options[:hide_navbar]
     - if (controller_name == "exercises" && action_name == "implement")
       .container-fluid
         = yield
diff --git a/app/views/proxy_exercises/_form.html.slim b/app/views/proxy_exercises/_form.html.slim
index 601ef950..831fb17e 100644
--- a/app/views/proxy_exercises/_form.html.slim
+++ b/app/views/proxy_exercises/_form.html.slim
@@ -6,6 +6,10 @@
   .form-group
     = f.label(:description)
     = f.pagedown :description, input_html: { preview: true, rows: 10 }
+  .form-check.mb-3
+    label.form-check-label
+      = f.check_box(:public, class: 'form-check-input')
+      = t('activerecord.attributes.exercise.public')
 
   h3 Exercises
   .table-responsive
diff --git a/app/views/proxy_exercises/index.html.slim b/app/views/proxy_exercises/index.html.slim
index a2e7e460..198ff991 100644
--- a/app/views/proxy_exercises/index.html.slim
+++ b/app/views/proxy_exercises/index.html.slim
@@ -11,13 +11,17 @@ h1 = ProxyExercise.model_name.human(count: 2)
       tr
         th.p-1 = sort_link(@search, :title, t('activerecord.attributes.proxy_exercise.title'))
         th.p-1 = t('activerecord.attributes.exercise.token')
+        th.p-1 = t('activerecord.attributes.exercise.public')
         th.p-1 = t('activerecord.attributes.proxy_exercise.files_count')
         th.p-1 colspan=6 = t('shared.actions')
     tbody
       - @proxy_exercises.each do |proxy_exercise|
         tr data-id=proxy_exercise.id
           td.p-1.pt-2 = link_to(proxy_exercise.title,proxy_exercise)
-          td.p-1.pt-2 = proxy_exercise.token
+          td.p-1.pt-2
+            code
+              = proxy_exercise.token
+          td.p-1.pt-2.public data-value=proxy_exercise.public? = symbol_for(proxy_exercise.public?)
           td.p-1.pt-2 = proxy_exercise.count_files
           td.p-1.pt-2 = link_to(t('shared.edit'), edit_proxy_exercise_path(proxy_exercise)) if policy(proxy_exercise).edit?
 
diff --git a/app/views/proxy_exercises/show.html.slim b/app/views/proxy_exercises/show.html.slim
index 07f5061a..4868443c 100644
--- a/app/views/proxy_exercises/show.html.slim
+++ b/app/views/proxy_exercises/show.html.slim
@@ -11,9 +11,12 @@ h1
     = render('shared/edit_button', object: @proxy_exercise)
 
 = row(label: 'exercise.title', value: @proxy_exercise.title)
+= row(label: 'exercise.user', value: link_to_if(policy(@proxy_exercise.author).show?, @proxy_exercise.author, @proxy_exercise.author))
 = row(label: 'proxy_exercise.files_count', value: @exercises.count)
+= row(label: 'exercise.public', value: @proxy_exercise.public?)
 = row(label: 'exercise.description', value: @proxy_exercise.description)
-= row(label: 'exercise.token', value: @proxy_exercise.token)
+= row(label: 'exercise.embedding_parameters', class: 'mb-4') do
+  = content_tag(:input, nil, class: 'form-control mb-4', readonly: true, value: embedding_parameters(@proxy_exercise))
 
 h2.mt-4 Exercises
 .table-responsive
diff --git a/app/views/submissions/show.json.jbuilder b/app/views/submissions/show.json.jbuilder
index 07e199f4..b66919dc 100644
--- a/app/views/submissions/show.json.jbuilder
+++ b/app/views/submissions/show.json.jbuilder
@@ -1,8 +1,8 @@
 json.extract! @submission, :id, :files
-json.download_url download_submission_path(@submission)
-json.score_url score_submission_path(@submission)
-json.stop_url stop_submission_path(@submission)
-json.download_file_url download_file_submission_path(@submission, 'a.').gsub(/a\.$/, '{filename}')
-json.render_url render_submission_path(@submission, 'a.').gsub(/a\.$/, '{filename}')
-json.run_url run_submission_path(@submission, 'a.').gsub(/a\.$/, '{filename}')
-json.test_url test_submission_path(@submission, 'a.').gsub(/a\.$/, '{filename}')
+json.download_url download_submission_path(@submission, format: :json)
+json.score_url score_submission_path(@submission, format: :json)
+json.stop_url stop_submission_path(@submission, format: :json)
+json.download_file_url download_file_submission_path(@submission, 'a.', format: :json).gsub(/a\.\.json$/, '{filename}.json')
+json.render_url render_submission_path(@submission, 'a.', format: :json).gsub(/a\.\.json$/, '{filename}.json')
+json.run_url run_submission_path(@submission, 'a.', format: :json).gsub(/a\.\.json$/, '{filename}.json')
+json.test_url test_submission_path(@submission, 'a.', format: :json).gsub(/a\.\.json$/, '{filename}.json')
diff --git a/app/views/user_exercise_feedbacks/index.html.slim b/app/views/user_exercise_feedbacks/index.html.slim
index 52249229..a9e6b33b 100644
--- a/app/views/user_exercise_feedbacks/index.html.slim
+++ b/app/views/user_exercise_feedbacks/index.html.slim
@@ -19,7 +19,7 @@ h1 = UserExerciseFeedback.model_name.human(count: 2)
       - @uefs.each do |uef|
         tr
           td = uef.user.id
-          td = uef.user.name
+          td = uef.user.displayname
           td = link_to(uef.exercise.title, uef.exercise)
           td = link_to(t('shared.show'), uef)
           td = link_to(t('shared.destroy'), uef, data: {confirm: t('shared.confirm_destroy')}, method: :delete)
diff --git a/app/views/user_mailer/send_thank_you_note.slim b/app/views/user_mailer/send_thank_you_note.slim
index fcdcdf8d..465e3083 100644
--- a/app/views/user_mailer/send_thank_you_note.slim
+++ b/app/views/user_mailer/send_thank_you_note.slim
@@ -1 +1 @@
-== t('mailers.user_mailer.send_thank_you_note.body', receiver_displayname: @receiver_displayname, link_to_comment: link_to(@rfc_link, @rfc_link), author: @author, thank_you_note: @thank_you_note )
+== t('mailers.user_mailer.send_thank_you_note.body', receiver_displayname: @receiver_displayname, link_to_comment: link_to(@rfc_link, @rfc_link), author: @author.displayname, thank_you_note: @thank_you_note )
diff --git a/config/locales/de.yml b/config/locales/de.yml
index 4cbd120c..f385a3d3 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -300,7 +300,7 @@ de:
       file: 'Test-Datei <span class="number">%{number}</span> (<span class="filename">%{filename}</span>)'
       hint: Tipp
       no_files: Die Aufgabe umfasst noch keine sichtbaren Dateien.
-      no_output: Die letzte Code-Ausführung hat keine Ausgabe erzeugt.
+      no_output: Die letzte Code-Ausführung terminierte am %{timestamp} ohne Ausgabe.
       no_output_yet: Bisher existiert noch keine Ausgabe.
       output: Programm-Ausgabe
       passed_tests: Erfolgreiche Tests
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 40922a02..0bcfd014 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -300,7 +300,7 @@ en:
       file: 'Test File <span class="number">%{number}</span> (<span class="filename">%{filename}</span>)'
       hint: Hint
       no_files: The exercise does not comprise visible files yet.
-      no_output: The last code run has not generated any output.
+      no_output: The last code run finished on %{timestamp} without any output.
       no_output_yet: There is no output yet.
       output: Program Output
       passed_tests: Passed Tests
diff --git a/config/routes.rb b/config/routes.rb
index 4b1a4719..dd3e16c5 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -150,7 +150,7 @@ Rails.application.routes.draw do
   post '/lti/launch', as: 'lti_launch', to: 'sessions#create_through_lti'
   get '/lti/return', as: 'lti_return', to: 'sessions#destroy_through_lti'
   get '/sign_in', as: 'sign_in', to: 'sessions#new'
-  delete '/sign_out', as: 'sign_out', to: 'sessions#destroy'
+  match '/sign_out', as: 'sign_out', to: 'sessions#destroy', via: [:get, :delete]
 
   resources :submissions, only: [:create, :index, :show] do
     member do
diff --git a/db/migrate/20181119161514_add_user_to_proxy_exercise.rb b/db/migrate/20181119161514_add_user_to_proxy_exercise.rb
new file mode 100644
index 00000000..983ce778
--- /dev/null
+++ b/db/migrate/20181119161514_add_user_to_proxy_exercise.rb
@@ -0,0 +1,9 @@
+class AddUserToProxyExercise < ActiveRecord::Migration[5.2]
+  def change
+    add_reference :proxy_exercises, :user,  polymorphic: true, index: true
+    add_column :proxy_exercises, :public, :boolean, null: false, default: false
+
+    internal_user = InternalUser.find_by(id: 46) || InternalUser.first
+    ProxyExercise.update_all(user_id: internal_user.id, user_type: internal_user.class.name)
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 3435e610..523bf8bb 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -263,6 +263,10 @@ ActiveRecord::Schema.define(version: 2018_11_29_093207) do
     t.string "token"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.string "user_type"
+    t.bigint "user_id"
+    t.boolean "public"
+    t.index ["user_type", "user_id"], name: "index_proxy_exercises_on_user_type_and_user_id"
   end
 
   create_table "remote_evaluation_mappings", force: :cascade do |t|
diff --git a/lib/assets/javascripts/flash.js b/lib/assets/javascripts/flash.js
index d7273864..7e7669a2 100644
--- a/lib/assets/javascripts/flash.js
+++ b/lib/assets/javascripts/flash.js
@@ -1,5 +1,5 @@
 $( document ).on('turbolinks:load', function() {
-  var DURATION = 10000;
+  var DURATION = 5000;
   var SEVERITIES = ['danger', 'info', 'success', 'warning'];
 
   var buildFlash = function(options) {
diff --git a/lib/assets/stylesheets/flash.css.scss b/lib/assets/stylesheets/flash.css.scss
index 0abb6dc9..d339aff2 100644
--- a/lib/assets/stylesheets/flash.css.scss
+++ b/lib/assets/stylesheets/flash.css.scss
@@ -1,6 +1,5 @@
 #flash-container {
   position: relative;
-  top: -21px;
 }
 
 .flash {
diff --git a/spec/concerns/lti_spec.rb b/spec/concerns/lti_spec.rb
index bdc5901e..37bb170f 100644
--- a/spec/concerns/lti_spec.rb
+++ b/spec/concerns/lti_spec.rb
@@ -19,6 +19,7 @@ describe Lti do
     it 'clears the session' do
       expect(controller.session).to receive(:delete).with(:consumer_id)
       expect(controller.session).to receive(:delete).with(:external_user_id)
+      expect(controller.session).to receive(:delete).with(:embed_options)
       controller.send(:clear_lti_session_data)
     end
   end
diff --git a/spec/controllers/submissions_controller_spec.rb b/spec/controllers/submissions_controller_spec.rb
index 6aaf8555..97dd2eb3 100644
--- a/spec/controllers/submissions_controller_spec.rb
+++ b/spec/controllers/submissions_controller_spec.rb
@@ -186,7 +186,7 @@ describe SubmissionsController do
         end
 
         it 'ends with a placeholder' do
-          expect(url).to end_with(Submission::FILENAME_URL_PLACEHOLDER)
+          expect(url).to end_with(Submission::FILENAME_URL_PLACEHOLDER + '.json')
         end
       end
     end
@@ -196,7 +196,7 @@ describe SubmissionsController do
         let(:url) { JSON.parse(response.body).with_indifferent_access.fetch("#{action}_url") }
 
         it "corresponds to the #{action} path" do
-          expect(url).to eq(Rails.application.routes.url_helpers.send(:"#{action}_submission_path", submission))
+          expect(url).to eq(Rails.application.routes.url_helpers.send(:"#{action}_submission_path", submission, format: :json))
         end
       end
     end
diff --git a/spec/factories/proxy_exercise.rb b/spec/factories/proxy_exercise.rb
index 3927541f..3118da81 100644
--- a/spec/factories/proxy_exercise.rb
+++ b/spec/factories/proxy_exercise.rb
@@ -1,5 +1,6 @@
 FactoryBot.define do
   factory :proxy_exercise, class: ProxyExercise do
+    created_by_teacher
     token { 'dummytoken' }
     title { 'Dummy' }
   end
diff --git a/spec/features/authentication_spec.rb b/spec/features/authentication_spec.rb
index 2a777dab..1cd08727 100644
--- a/spec/features/authentication_spec.rb
+++ b/spec/features/authentication_spec.rb
@@ -38,8 +38,8 @@ describe 'Authentication' do
       visit(root_path)
     end
 
-    it "displays the user's name" do
-      expect(page).to have_content(user.name)
+    it "displays the user's displayname" do
+      expect(page).to have_content(user.displayname)
     end
 
     it 'displays a sign out link' do
diff --git a/spec/views/exercises/implement.html.slim_spec.rb b/spec/views/exercises/implement.html.slim_spec.rb
index fe9ab0d0..1944aa31 100644
--- a/spec/views/exercises/implement.html.slim_spec.rb
+++ b/spec/views/exercises/implement.html.slim_spec.rb
@@ -10,6 +10,7 @@ describe 'exercises/implement.html.slim' do
     assign(:exercise, exercise)
     assign(:files, files)
     assign(:paths, [])
+    assign(:embed_options, {})
     render
   end