diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -9,10 +9,10 @@
   'names' => array(
     'conpherence.pkg.css' => '3c8a0668',
     'conpherence.pkg.js' => '020aebcf',
-    'core.pkg.css' => '6a8c9533',
+    'core.pkg.css' => '19ec9519',
     'core.pkg.js' => '6e5c894f',
-    'differential.pkg.css' => 'abd2c0d8',
-    'differential.pkg.js' => '68fa36fc',
+    'differential.pkg.css' => '607c84be',
+    'differential.pkg.js' => 'a0212a0b',
     'diffusion.pkg.css' => '42c75c37',
     'diffusion.pkg.js' => 'a98c0bf7',
     'maniphest.pkg.css' => '35995d6d',
@@ -61,7 +61,7 @@
     'rsrc/css/application/dashboard/dashboard.css' => '5a205b9d',
     'rsrc/css/application/diff/inline-comment-summary.css' => '81eb368d',
     'rsrc/css/application/differential/add-comment.css' => '7e5900d9',
-    'rsrc/css/application/differential/changeset-view.css' => '5dda5e53',
+    'rsrc/css/application/differential/changeset-view.css' => '489b6995',
     'rsrc/css/application/differential/core.css' => '7300a73e',
     'rsrc/css/application/differential/phui-inline-comment.css' => '48acce5b',
     'rsrc/css/application/differential/revision-comment.css' => '7dbc8d1d',
@@ -113,7 +113,7 @@
     'rsrc/css/application/uiexample/example.css' => 'b4795059',
     'rsrc/css/core/core.css' => '1b29ed61',
     'rsrc/css/core/remarkup.css' => 'f06cc20e',
-    'rsrc/css/core/syntax.css' => '4234f572',
+    'rsrc/css/core/syntax.css' => '220b85f9',
     'rsrc/css/core/z-index.css' => '99c0f5eb',
     'rsrc/css/diviner/diviner-shared.css' => '4bd263b0',
     'rsrc/css/font/font-awesome.css' => '3883938a',
@@ -169,7 +169,7 @@
     'rsrc/css/phui/phui-pager.css' => 'd022c7ad',
     'rsrc/css/phui/phui-pinboard-view.css' => '1f08f5d8',
     'rsrc/css/phui/phui-policy-section-view.css' => '139fdc64',
-    'rsrc/css/phui/phui-property-list-view.css' => '34180764',
+    'rsrc/css/phui/phui-property-list-view.css' => 'ad841f1c',
     'rsrc/css/phui/phui-remarkup-preview.css' => '91767007',
     'rsrc/css/phui/phui-segment-bar-view.css' => '5166b370',
     'rsrc/css/phui/phui-spacing.css' => 'b05cadc3',
@@ -377,7 +377,7 @@
     'rsrc/js/application/dashboard/behavior-dashboard-query-panel-select.js' => '1e413dc9',
     'rsrc/js/application/dashboard/behavior-dashboard-tab-panel.js' => '0116d3e8',
     'rsrc/js/application/diff/DiffChangeset.js' => 'a31ffc00',
-    'rsrc/js/application/diff/DiffChangesetList.js' => '22f6bb51',
+    'rsrc/js/application/diff/DiffChangesetList.js' => '0f5c016d',
     'rsrc/js/application/diff/DiffInline.js' => 'a4a14a94',
     'rsrc/js/application/diff/behavior-preview-link.js' => 'f51e9c17',
     'rsrc/js/application/differential/behavior-diff-radios.js' => '925fe8cd',
@@ -554,7 +554,7 @@
     'conpherence-thread-manager' => 'aec8e38c',
     'conpherence-transaction-css' => '3a3f5e7e',
     'd3' => '9d068042',
-    'differential-changeset-view-css' => '5dda5e53',
+    'differential-changeset-view-css' => '489b6995',
     'differential-core-view-css' => '7300a73e',
     'differential-revision-add-comment-css' => '7e5900d9',
     'differential-revision-comment-css' => '7dbc8d1d',
@@ -774,7 +774,7 @@
     'phabricator-darkmessage' => '26cd4b73',
     'phabricator-dashboard-css' => '5a205b9d',
     'phabricator-diff-changeset' => 'a31ffc00',
-    'phabricator-diff-changeset-list' => '22f6bb51',
+    'phabricator-diff-changeset-list' => '0f5c016d',
     'phabricator-diff-inline' => 'a4a14a94',
     'phabricator-drag-and-drop-file-upload' => '4370900d',
     'phabricator-draggable-list' => 'c9ad6f70',
@@ -865,7 +865,7 @@
     'phui-pager-css' => 'd022c7ad',
     'phui-pinboard-view-css' => '1f08f5d8',
     'phui-policy-section-view-css' => '139fdc64',
-    'phui-property-list-view-css' => '34180764',
+    'phui-property-list-view-css' => 'ad841f1c',
     'phui-remarkup-preview-css' => '91767007',
     'phui-segment-bar-view-css' => '5166b370',
     'phui-spacing-css' => 'b05cadc3',
@@ -900,7 +900,7 @@
     'sprite-login-css' => '18b368a6',
     'sprite-tokens-css' => 'f1896dc5',
     'syntax-default-css' => '055fc231',
-    'syntax-highlighting-css' => '4234f572',
+    'syntax-highlighting-css' => '220b85f9',
     'tokens-css' => 'ce5a50bd',
     'trigger-rule' => '41b7b4f6',
     'trigger-rule-control' => '5faf27b9',
@@ -1005,6 +1005,10 @@
       'javelin-workflow',
       'phuix-icon-view',
     ),
+    '0f5c016d' => array(
+      'javelin-install',
+      'phuix-button-view',
+    ),
     '111bfd2d' => array(
       'javelin-install',
     ),
@@ -1065,6 +1069,9 @@
       'javelin-behavior',
       'javelin-request',
     ),
+    '220b85f9' => array(
+      'syntax-default-css',
+    ),
     '225bbb98' => array(
       'javelin-install',
       'javelin-reactor',
@@ -1075,10 +1082,6 @@
       'javelin-typeahead-source',
       'javelin-util',
     ),
-    '22f6bb51' => array(
-      'javelin-install',
-      'phuix-button-view',
-    ),
     23387297 => array(
       'javelin-install',
       'javelin-util',
@@ -1260,9 +1263,6 @@
       'javelin-behavior',
       'javelin-uri',
     ),
-    '4234f572' => array(
-      'syntax-default-css',
-    ),
     '4370900d' => array(
       'javelin-install',
       'javelin-util',
@@ -1303,6 +1303,9 @@
       'javelin-dom',
       'phabricator-draggable-list',
     ),
+    '489b6995' => array(
+      'phui-inline-comment-view-css',
+    ),
     '48fe33d0' => array(
       'javelin-behavior',
       'javelin-dom',
@@ -1457,9 +1460,6 @@
       'javelin-dom',
       'phuix-dropdown-menu',
     ),
-    '5dda5e53' => array(
-      'phui-inline-comment-view-css',
-    ),
     '5faf27b9' => array(
       'phuix-form-control-view',
     ),
diff --git a/src/applications/differential/render/DifferentialChangesetTwoUpRenderer.php b/src/applications/differential/render/DifferentialChangesetTwoUpRenderer.php
--- a/src/applications/differential/render/DifferentialChangesetTwoUpRenderer.php
+++ b/src/applications/differential/render/DifferentialChangesetTwoUpRenderer.php
@@ -387,6 +387,8 @@
           $old_classes[] = 'old-full';
         }
 
+        $old_classes[] = 'diff-flush';
+
         $old_classes = implode(' ', $old_classes);
       } else {
         $old_content = null;
@@ -404,6 +406,8 @@
           $new_classes[] = 'new-full';
         }
 
+        $new_classes[] = 'diff-flush';
+
         $new_classes = implode(' ', $new_classes);
       } else {
         $new_content = null;
@@ -451,6 +455,7 @@
         'td',
         array(
           'class' => $old_classes,
+          'data-copy-mode' => 'copy-l',
         ),
         $old_content);
 
@@ -479,6 +484,7 @@
         array(
           'class' => $new_classes,
           'colspan' => '2',
+          'data-copy-mode' => 'copy-r',
         ),
         $new_content);
 
diff --git a/src/applications/files/document/PhabricatorJupyterDocumentEngine.php b/src/applications/files/document/PhabricatorJupyterDocumentEngine.php
--- a/src/applications/files/document/PhabricatorJupyterDocumentEngine.php
+++ b/src/applications/files/document/PhabricatorJupyterDocumentEngine.php
@@ -57,11 +57,7 @@
     $viewer = $this->getViewer();
     $content = $ref->loadData();
 
-    $data = phutil_json_decode($content);
-    $cells = idx($data, 'cells');
-    if (!is_array($cells)) {
-      throw new Exception('Missing "cells".');
-    }
+    $cells = $this->newCells($content, true);
 
     $idx = 1;
     $blocks = array();
@@ -82,8 +78,20 @@
         ),
         $notebook_table);
 
+      // When the cell is a source code line, we can hash just the raw
+      // input rather than all the cell metadata.
+
+      switch (idx($cell, 'cell_type')) {
+        case 'code/line':
+          $hash_input = $cell['raw'];
+          break;
+        default:
+          $hash_input = serialize($cell);
+          break;
+      }
+
       $hash = PhabricatorHash::digestWithNamedKey(
-        serialize($cell),
+        $hash_input,
         'document-engine.content-digest');
 
       $blocks[] = id(new PhabricatorDocumentEngineBlock())
@@ -101,10 +109,39 @@
     $viewer = $this->getViewer();
     $content = $ref->loadData();
 
+    try {
+      $cells = $this->newCells($content, false);
+    } catch (Exception $ex) {
+      return $this->newMessage($ex->getMessage());
+    }
+
+    $rows = array();
+    foreach ($cells as $cell) {
+      $rows[] = $this->renderJupyterCell($viewer, $cell);
+    }
+
+    $notebook_table = phutil_tag(
+      'table',
+      array(
+        'class' => 'jupyter-notebook',
+      ),
+      $rows);
+
+    $container = phutil_tag(
+      'div',
+      array(
+        'class' => 'document-engine-jupyter',
+      ),
+      $notebook_table);
+
+    return $container;
+  }
+
+  private function newCells($content, $for_diff) {
     try {
       $data = phutil_json_decode($content);
     } catch (PhutilJSONParserException $ex) {
-      return $this->newMessage(
+      throw new Exception(
         pht(
           'This is not a valid JSON document and can not be rendered as '.
           'a Jupyter notebook: %s.',
@@ -112,7 +149,7 @@
     }
 
     if (!is_array($data)) {
-      return $this->newMessage(
+      throw new Exception(
         pht(
           'This document does not encode a valid JSON object and can not '.
           'be rendered as a Jupyter notebook.'));
@@ -121,14 +158,14 @@
 
     $nbformat = idx($data, 'nbformat');
     if (!strlen($nbformat)) {
-      return $this->newMessage(
+      throw new Exception(
         pht(
           'This document is missing an "nbformat" field. Jupyter notebooks '.
           'must have this field.'));
     }
 
     if ($nbformat !== 4) {
-      return $this->newMessage(
+      throw new Exception(
         pht(
           'This Jupyter notebook uses an unsupported version of the file '.
           'format (found version %s, expected version 4).',
@@ -137,39 +174,80 @@
 
     $cells = idx($data, 'cells');
     if (!is_array($cells)) {
-      return $this->newMessage(
+      throw new Exception(
         pht(
           'This Jupyter notebook does not specify a list of "cells".'));
     }
 
     if (!$cells) {
-      return $this->newMessage(
+      throw new Exception(
         pht(
           'This Jupyter notebook does not specify any notebook cells.'));
     }
 
-    $rows = array();
-    foreach ($cells as $cell) {
-      $rows[] = $this->renderJupyterCell($viewer, $cell);
+    if (!$for_diff) {
+      return $cells;
     }
 
-    $notebook_table = phutil_tag(
-      'table',
-      array(
-        'class' => 'jupyter-notebook',
-      ),
-      $rows);
+    // If we're extracting cells to build a diff view, split code cells into
+    // individual lines and individual outputs. We want users to be able to
+    // add inline comments to each line and each output block.
 
-    $container = phutil_tag(
-      'div',
-      array(
-        'class' => 'document-engine-jupyter',
-      ),
-      $notebook_table);
+    $results = array();
+    foreach ($cells as $cell) {
+      $cell_type = idx($cell, 'cell_type');
 
-    return $container;
+      if ($cell_type !== 'code') {
+        $results[] = $cell;
+        continue;
+      }
+
+      $label = $this->newCellLabel($cell);
+
+      $lines = idx($cell, 'source');
+      if (!is_array($lines)) {
+        $lines = array();
+      }
+
+      $content = $this->highlightLines($lines);
+
+      $count = count($lines);
+      for ($ii = 0; $ii < $count; $ii++) {
+        $is_head = ($ii === 0);
+        $is_last = ($ii === ($count - 1));
+
+        if ($is_head) {
+          $line_label = $label;
+        } else {
+          $line_label = null;
+        }
+
+        $results[] = array(
+          'cell_type' => 'code/line',
+          'label' => $line_label,
+          'raw' => $lines[$ii],
+          'display' => idx($content, $ii),
+          'head' => $is_head,
+          'last' => $is_last,
+        );
+      }
+
+      $outputs = array();
+      $output_list = idx($cell, 'outputs');
+      if (is_array($output_list)) {
+        foreach ($output_list as $output) {
+          $results[] = array(
+            'cell_type' => 'code/output',
+            'output' => $output,
+          );
+        }
+      }
+    }
+
+    return $results;
   }
 
+
   private function renderJupyterCell(
     PhabricatorUser $viewer,
     array $cell) {
@@ -177,13 +255,24 @@
     list($label, $content) = $this->renderJupyterCellContent($viewer, $cell);
 
     $label_cell = phutil_tag(
-      'th',
-      array(),
+      'td',
+      array(
+        'class' => 'jupyter-label',
+      ),
       $label);
 
+    $classes = null;
+    switch (idx($cell, 'cell_type')) {
+      case 'code/line':
+        $classes = 'jupyter-cell-flush';
+        break;
+    }
+
     $content_cell = phutil_tag(
       'td',
-      array(),
+      array(
+        'class' => $classes,
+      ),
       $content);
 
     return phutil_tag(
@@ -204,7 +293,11 @@
       case 'markdown':
         return $this->newMarkdownCell($cell);
       case 'code':
-       return $this->newCodeCell($cell);
+        return $this->newCodeCell($cell);
+      case 'code/line':
+        return $this->newCodeLineCell($cell);
+      case 'code/output':
+        return $this->newCodeOutputCell($cell);
     }
 
     return $this->newRawCell(id(new PhutilJSON())->encodeFormatted($cell));
@@ -243,23 +336,14 @@
   }
 
   private function newCodeCell(array $cell) {
-    $execution_count = idx($cell, 'execution_count');
-    if ($execution_count) {
-      $label = 'In ['.$execution_count.']:';
-    } else {
-      $label = null;
-    }
+    $label = $this->newCellLabel($cell);
 
     $content = idx($cell, 'source');
     if (!is_array($content)) {
       $content = array();
     }
 
-    $content = implode('', $content);
-
-    $content = PhabricatorSyntaxHighlighter::highlightWithLanguage(
-      'py',
-      $content);
+    $content = $this->highlightLines($content);
 
     $outputs = array();
     $output_list = idx($cell, 'outputs');
@@ -275,7 +359,9 @@
         phutil_tag(
           'div',
           array(
-            'class' => 'jupyter-cell-code PhabricatorMonospaced remarkup-code',
+            'class' =>
+              'jupyter-cell-code jupyter-cell-code-block '.
+              'PhabricatorMonospaced remarkup-code',
           ),
           array(
             $content,
@@ -285,6 +371,45 @@
     );
   }
 
+  private function newCodeLineCell(array $cell) {
+    $classes = array();
+    $classes[] = 'PhabricatorMonospaced';
+    $classes[] = 'remarkup-code';
+    $classes[] = 'jupyter-cell-code';
+    $classes[] = 'jupyter-cell-code-line';
+
+    if ($cell['head']) {
+      $classes[] = 'jupyter-cell-code-head';
+    }
+
+    if ($cell['last']) {
+      $classes[] = 'jupyter-cell-code-last';
+    }
+
+    $classes = implode(' ', $classes);
+
+    return array(
+      $cell['label'],
+      array(
+        phutil_tag(
+          'div',
+          array(
+            'class' => $classes,
+          ),
+          array(
+            $cell['display'],
+          )),
+      ),
+    );
+  }
+
+  private function newCodeOutputCell(array $cell) {
+    return array(
+      null,
+      $this->newOutput($cell['output']),
+    );
+  }
+
   private function newOutput(array $output) {
     if (!is_array($output)) {
       return pht('<Invalid Output>');
@@ -371,4 +496,45 @@
       $content);
   }
 
+  private function newCellLabel(array $cell) {
+    $execution_count = idx($cell, 'execution_count');
+    if ($execution_count) {
+      $label = 'In ['.$execution_count.']:';
+    } else {
+      $label = null;
+    }
+
+    return $label;
+  }
+
+  private function highlightLines(array $lines) {
+    $head = head($lines);
+    $matches = null;
+    if (preg_match('/^%%(.*)$/', $head, $matches)) {
+      $restore = array_shift($lines);
+      $lang = $matches[1];
+    } else {
+      $restore = null;
+      $lang = 'py';
+    }
+
+    $content = PhabricatorSyntaxHighlighter::highlightWithLanguage(
+      $lang,
+      implode('', $lines));
+    $content = phutil_split_lines($content);
+
+    if ($restore !== null) {
+      $language_tag = phutil_tag(
+        'span',
+        array(
+          'class' => 'language-tag',
+        ),
+        $restore);
+
+      array_unshift($content, $language_tag);
+    }
+
+    return $content;
+  }
+
 }
diff --git a/webroot/rsrc/css/application/differential/changeset-view.css b/webroot/rsrc/css/application/differential/changeset-view.css
--- a/webroot/rsrc/css/application/differential/changeset-view.css
+++ b/webroot/rsrc/css/application/differential/changeset-view.css
@@ -63,6 +63,11 @@
   padding: 1px 8px;
 }
 
+.differential-diff td.diff-flush {
+  padding-top: 0;
+  padding-bottom: 0;
+}
+
 .device .differential-diff td {
   padding: 1px 4px;
 }
diff --git a/webroot/rsrc/css/core/syntax.css b/webroot/rsrc/css/core/syntax.css
--- a/webroot/rsrc/css/core/syntax.css
+++ b/webroot/rsrc/css/core/syntax.css
@@ -6,6 +6,10 @@
   color: #aa0066;
 }
 
+.remarkup-code .language-tag {
+  color: {$lightgreytext};
+}
+
 .remarkup-code td > span {
   display: inline;
   word-break: break-all;
diff --git a/webroot/rsrc/css/phui/phui-property-list-view.css b/webroot/rsrc/css/phui/phui-property-list-view.css
--- a/webroot/rsrc/css/phui/phui-property-list-view.css
+++ b/webroot/rsrc/css/phui/phui-property-list-view.css
@@ -298,22 +298,56 @@
 
 .jupyter-cell-code {
   white-space: pre-wrap;
+  word-break: break-word;
   background: {$lightgreybackground};
-  padding: 8px;
-  border: 1px solid {$lightgreyborder};
   border-radius: 2px;
+  border-color: {$lightgreyborder};
+  border-style: solid;
+}
+
+.jupyter-cell-code-block {
+  padding: 8px;
+  border-width: 1px;
+}
+
+.jupyter-cell-code-line {
+  padding: 2px 8px;
+  border-width: 0 1px;
+}
+
+.jupyter-cell-code-head {
+  border-top-width: 1px;
+  margin-top: 4px;
+  padding-top: 8px;
+}
+
+.jupyter-cell-code-last {
+  border-bottom-width: 1px;
+  margin-bottom: 4px;
+  padding-bottom: 8px;
 }
 
-.jupyter-notebook > tbody > tr > th,
 .jupyter-notebook > tbody > tr > td {
   padding: 8px;
 }
 
-.jupyter-notebook > tbody > tr > th {
+.jupyter-notebook > tbody > tr > td.jupyter-cell-flush {
+  padding-top: 0;
+  padding-bottom: 0;
+}
+
+.jupyter-notebook,
+.jupyter-notebook > tbody > tr > td {
+  width: 100%;
+}
+
+.jupyter-notebook > tbody > tr > td.jupyter-label {
   white-space: nowrap;
   text-align: right;
-  min-width: 48px;
+  min-width: 56px;
   font-weight: bold;
+  width: auto;
+  padding: 8px 8px 0;
 }
 
 .jupyter-output {
diff --git a/webroot/rsrc/js/application/diff/DiffChangesetList.js b/webroot/rsrc/js/application/diff/DiffChangesetList.js
--- a/webroot/rsrc/js/application/diff/DiffChangesetList.js
+++ b/webroot/rsrc/js/application/diff/DiffChangesetList.js
@@ -1195,41 +1195,26 @@
         bot = tmp;
       }
 
-      // Find the leftmost cell that we're going to highlight: this is the next
-      // <td /> in the row that does not have a "data-n" (line number)
-      // attribute. In 2up views, it should be directly adjacent. In
-      // 1up views, we may have to skip over the other line number column.
-      var l = top;
-      while (l.nextSibling && l.getAttribute('data-n')) {
-        l = l.nextSibling;
-      }
-
-      // Find the rightmost cell that we're going to highlight: this is the
-      // farthest consecutive, adjacent <td /> in the row that does not have
-      // a "data-n" (line number) attribute. Sometimes the left and right nodes
-      // are the same (left side of 2up view); sometimes we're going to
-      // highlight several nodes (copy + code + coverage).
-      var r = l;
-      while (true) {
-        // No more cells in the row, so we can't keep expanding.
-        if (!r.nextSibling) {
-          break;
-        }
-
-        if (r.nextSibling.getAttribute('data-n')) {
-          break;
-        }
+      // Find the leftmost cell that we're going to highlight. This is the
+      // next sibling with a "data-copy-mode" attribute, which is a marker
+      // for the cell with actual content in it.
+      var content_cell = top;
+      while (content_cell && !content_cell.getAttribute('data-copy-mode')) {
+        content_cell = content_cell.nextSibling;
+      }
 
-        r = r.nextSibling;
+      // If we didn't find a cell to highlight, don't highlight anything.
+      if (!content_cell) {
+        return;
       }
 
-      var pos = JX.$V(l)
-        .add(JX.Vector.getAggregateScrollForNode(l));
+      var pos = JX.$V(content_cell)
+        .add(JX.Vector.getAggregateScrollForNode(content_cell));
 
-      var dim = JX.$V(r)
-        .add(JX.Vector.getAggregateScrollForNode(r))
+      var dim = JX.$V(content_cell)
+        .add(JX.Vector.getAggregateScrollForNode(content_cell))
         .add(-pos.x, -pos.y)
-        .add(JX.Vector.getDim(r));
+        .add(JX.Vector.getDim(content_cell));
 
       var bpos = JX.$V(bot)
         .add(JX.Vector.getAggregateScrollForNode(bot));