diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -403,6 +403,7 @@
     'PhutilRemarkupLiteralBlockRule' => 'markup/engine/remarkup/blockrule/PhutilRemarkupLiteralBlockRule.php',
     'PhutilRemarkupMonospaceRule' => 'markup/engine/remarkup/markuprule/PhutilRemarkupMonospaceRule.php',
     'PhutilRemarkupNoteBlockRule' => 'markup/engine/remarkup/blockrule/PhutilRemarkupNoteBlockRule.php',
+    'PhutilRemarkupQuotedBlockRule' => 'markup/engine/remarkup/blockrule/PhutilRemarkupQuotedBlockRule.php',
     'PhutilRemarkupQuotesBlockRule' => 'markup/engine/remarkup/blockrule/PhutilRemarkupQuotesBlockRule.php',
     'PhutilRemarkupReplyBlockRule' => 'markup/engine/remarkup/blockrule/PhutilRemarkupReplyBlockRule.php',
     'PhutilRemarkupRule' => 'markup/engine/remarkup/markuprule/PhutilRemarkupRule.php',
@@ -1063,8 +1064,9 @@
     'PhutilRemarkupLiteralBlockRule' => 'PhutilRemarkupBlockRule',
     'PhutilRemarkupMonospaceRule' => 'PhutilRemarkupRule',
     'PhutilRemarkupNoteBlockRule' => 'PhutilRemarkupBlockRule',
-    'PhutilRemarkupQuotesBlockRule' => 'PhutilRemarkupBlockRule',
-    'PhutilRemarkupReplyBlockRule' => 'PhutilRemarkupBlockRule',
+    'PhutilRemarkupQuotedBlockRule' => 'PhutilRemarkupBlockRule',
+    'PhutilRemarkupQuotesBlockRule' => 'PhutilRemarkupQuotedBlockRule',
+    'PhutilRemarkupReplyBlockRule' => 'PhutilRemarkupQuotedBlockRule',
     'PhutilRemarkupRule' => 'Phobject',
     'PhutilRemarkupSimpleTableBlockRule' => 'PhutilRemarkupBlockRule',
     'PhutilRemarkupTableBlockRule' => 'PhutilRemarkupBlockRule',
diff --git a/src/markup/engine/__tests__/remarkup/quoted-code-block.txt b/src/markup/engine/__tests__/remarkup/quoted-code-block.txt
--- a/src/markup/engine/__tests__/remarkup/quoted-code-block.txt
+++ b/src/markup/engine/__tests__/remarkup/quoted-code-block.txt
@@ -11,6 +11,6 @@
 <span class="nv">$foo</span> <span class="k">=</span> <span class="s">&#039;bar&#039;</span><span class="k">;</span></pre></div></blockquote>
 ~~~~~~~~~~
 > This should be a code block:
-> 
+>
 >   <?php
 >   $foo = 'bar';
diff --git a/src/markup/engine/__tests__/remarkup/quoted-lists.txt b/src/markup/engine/__tests__/remarkup/quoted-lists.txt
--- a/src/markup/engine/__tests__/remarkup/quoted-lists.txt
+++ b/src/markup/engine/__tests__/remarkup/quoted-lists.txt
@@ -18,7 +18,7 @@
 ~~~~~~~~~~
 > 1. X
 > 2. Y
-> ~
+>
 > B
-> ~
+>
 > - C
diff --git a/src/markup/engine/__tests__/remarkup/quoted-quote.txt b/src/markup/engine/__tests__/remarkup/quoted-quote.txt
new file mode 100644
--- /dev/null
+++ b/src/markup/engine/__tests__/remarkup/quoted-quote.txt
@@ -0,0 +1,19 @@
+>>! In U, W wrote:
+> - Y
+>
+> Z
+~~~~~~~~~~
+<blockquote class="remarkup-reply-block">
+<div class="remarkup-reply-head">In U, W wrote:</div>
+<div class="remarkup-reply-body"><ul class="remarkup-list">
+<li class="remarkup-list-item">Y</li>
+</ul>
+
+<p>Z</p></div>
+</blockquote>
+~~~~~~~~~~
+In U, W wrote:
+
+> - Y
+>
+> Z
diff --git a/src/markup/engine/__tests__/remarkup/reply-basic.txt b/src/markup/engine/__tests__/remarkup/reply-basic.txt
--- a/src/markup/engine/__tests__/remarkup/reply-basic.txt
+++ b/src/markup/engine/__tests__/remarkup/reply-basic.txt
@@ -9,4 +9,3 @@
 In comment #123, alincoln wrote:
 
 > Four score and twenty years ago...
-
diff --git a/src/markup/engine/__tests__/remarkup/reply-nested.txt b/src/markup/engine/__tests__/remarkup/reply-nested.txt
--- a/src/markup/engine/__tests__/remarkup/reply-nested.txt
+++ b/src/markup/engine/__tests__/remarkup/reply-nested.txt
@@ -41,10 +41,8 @@
 >
 > More previously, vegetables:
 >
-> > - Potato
-> > - Potato
-> > - Potato
->
+>> - Potato
+>> - Potato
+>> - Potato
 >
 > The end.
-
diff --git a/src/markup/engine/remarkup/blockrule/PhutilRemarkupQuotedBlockRule.php b/src/markup/engine/remarkup/blockrule/PhutilRemarkupQuotedBlockRule.php
new file mode 100644
--- /dev/null
+++ b/src/markup/engine/remarkup/blockrule/PhutilRemarkupQuotedBlockRule.php
@@ -0,0 +1,108 @@
+<?php
+
+abstract class PhutilRemarkupQuotedBlockRule
+  extends PhutilRemarkupBlockRule {
+
+  final public function supportsChildBlocks() {
+    return true;
+  }
+
+  final protected function normalizeQuotedBody($text) {
+    $text = phutil_split_lines($text, true);
+    foreach ($text as $key => $line) {
+      $text[$key] = substr($line, 1);
+    }
+
+    // If every line in the block is empty or begins with at least one leading
+    // space, strip the initial space off each line. When we quote text, we
+    // normally add "> " (with a space) to the beginning of each line, which
+    // can disrupt some other rules. If the block appears to have this space
+    // in front of each line, remove it.
+
+    $strip_space = true;
+    foreach ($text as $key => $line) {
+      $len = strlen($line);
+
+      if (!$len) {
+        // We'll still strip spaces if there are some completely empty
+        // lines, they may have just had trailing whitespace trimmed.
+        continue;
+      }
+
+      // If this line is part of a nested quote block, just ignore it when
+      // realigning this quote block. It's either an author attribution
+      // line with ">>!", or we'll deal with it in a subrule when processing
+      // the nested quote block.
+      if ($line[0] == '>') {
+        continue;
+      }
+
+      if ($line[0] == ' ' || $line[0] == "\n") {
+        continue;
+      }
+
+      // The first character of this line is something other than a space, so
+      // we can't strip spaces.
+      $strip_space = false;
+      break;
+    }
+
+    if ($strip_space) {
+      foreach ($text as $key => $line) {
+        $len = strlen($line);
+        if (!$len) {
+          continue;
+        }
+
+        if ($line[0] !== ' ') {
+          continue;
+        }
+
+        $text[$key] = substr($line, 1);
+      }
+    }
+
+    // Strip leading empty lines.
+    foreach ($text as $key => $line) {
+      if (!strlen(trim($line))) {
+        unset($text[$key]);
+      }
+    }
+
+    return implode('', $text);
+  }
+
+  final protected function getQuotedText($text) {
+    $text = rtrim($text, "\n");
+
+    $no_whitespace = array(
+      // For readability, we render nested quotes as ">> quack",
+      // not "> > quack".
+      '>' => true,
+
+      // If the line is empty except for a newline, do not add an
+      // unnecessary dangling space.
+      "\n" => true,
+    );
+
+    $text = phutil_split_lines($text, true);
+    foreach ($text as $key => $line) {
+      $c = null;
+      if (isset($line[0])) {
+        $c = $line[0];
+      } else {
+        $c = null;
+      }
+
+      if (isset($no_whitespace[$c])) {
+        $text[$key] = '>'.$line;
+      } else {
+        $text[$key] = '> '.$line;
+      }
+    }
+    $text = implode('', $text);
+
+    return $text;
+  }
+
+}
diff --git a/src/markup/engine/remarkup/blockrule/PhutilRemarkupQuotesBlockRule.php b/src/markup/engine/remarkup/blockrule/PhutilRemarkupQuotesBlockRule.php
--- a/src/markup/engine/remarkup/blockrule/PhutilRemarkupQuotesBlockRule.php
+++ b/src/markup/engine/remarkup/blockrule/PhutilRemarkupQuotesBlockRule.php
@@ -1,6 +1,7 @@
 <?php
 
-final class PhutilRemarkupQuotesBlockRule extends PhutilRemarkupBlockRule {
+final class PhutilRemarkupQuotesBlockRule
+  extends PhutilRemarkupQuotedBlockRule {
 
   public function getMatchingLineCount(array $lines, $cursor) {
     $pos = $cursor;
@@ -14,73 +15,13 @@
     return ($pos - $cursor);
   }
 
-  public function supportsChildBlocks() {
-    return true;
-  }
-
   public function extractChildText($text) {
-    $text = phutil_split_lines($text, true);
-    foreach ($text as $key => $line) {
-      $text[$key] = substr($line, 1);
-    }
-
-    // If every line in the block is empty or begins with at least one leading
-    // space, strip the initial space off each line. When we quote text, we
-    // normally add "> " (with a space) to the beginning of each line, which
-    // can disrupt some other rules. If the block appears to have this space
-    // in front of each line, remove it.
-
-    $strip_space = true;
-    foreach ($text as $key => $line) {
-      $len = strlen($line);
-
-      if (!$len) {
-        // We'll still strip spaces if there are some completely empty
-        // lines, they may have just had trailing whitespace trimmed.
-        continue;
-      }
-
-      if ($line[0] == ' ' || $line[0] == "\n") {
-        continue;
-      }
-
-      // The first character of this line is something other than a space, so
-      // we can't strip spaces.
-      $strip_space = false;
-      break;
-    }
-
-    if ($strip_space) {
-      foreach ($text as $key => $line) {
-        $len = strlen($line);
-        if (!$len) {
-          continue;
-        }
-
-        if ($line[0] !== ' ') {
-          continue;
-        }
-
-        $text[$key] = substr($line, 1);
-      }
-    }
-
-    return array('', implode('', $text));
+    return array('', $this->normalizeQuotedBody($text));
   }
 
   public function markupText($text, $children) {
     if ($this->getEngine()->isTextMode()) {
-      $lines = rtrim($children, "\n");
-      $lines = phutil_split_lines($lines);
-      foreach ($lines as $key => $line) {
-        if (isset($line[0]) && ($line[0] == '>')) {
-          $line = '>'.$line;
-        } else {
-          $line = '> '.$line;
-        }
-        $lines[$key] = $line;
-      }
-      return implode('', $lines);
+      return $this->getQuotedText($children);
     }
 
     $attributes = array();
diff --git a/src/markup/engine/remarkup/blockrule/PhutilRemarkupReplyBlockRule.php b/src/markup/engine/remarkup/blockrule/PhutilRemarkupReplyBlockRule.php
--- a/src/markup/engine/remarkup/blockrule/PhutilRemarkupReplyBlockRule.php
+++ b/src/markup/engine/remarkup/blockrule/PhutilRemarkupReplyBlockRule.php
@@ -1,6 +1,7 @@
 <?php
 
-final class PhutilRemarkupReplyBlockRule extends PhutilRemarkupBlockRule {
+final class PhutilRemarkupReplyBlockRule
+  extends PhutilRemarkupQuotedBlockRule {
 
   public function getPriority() {
     return 400;
@@ -18,50 +19,23 @@
     return ($pos - $cursor);
   }
 
-  public function supportsChildBlocks() {
-    return true;
-  }
-
   public function extractChildText($text) {
     $text = phutil_split_lines($text, true);
 
-    $head = array();
-    $body = array();
-
     $head = substr(reset($text), 3);
 
     $body = array_slice($text, 1);
+    $body = implode('', $body);
+    $body = $this->normalizeQuotedBody($body);
 
-    // Remove the carets.
-    foreach ($body as $key => $line) {
-      $body[$key] = substr($line, 1);
-    }
-
-    // Strip leading empty lines.
-    foreach ($body as $key => $line) {
-      if (strlen(trim($line))) {
-        break;
-      }
-      unset($body[$key]);
-    }
-
-    return array(trim($head), implode('', $body));
+    return array(trim($head), $body);
   }
 
   public function markupText($text, $children) {
     $text = $this->applyRules($text);
 
     if ($this->getEngine()->isTextMode()) {
-      $children = phutil_split_lines($children, true);
-      foreach ($children as $key => $child) {
-        if (strlen(trim($child))) {
-          $children[$key] = '> '.$child;
-        } else {
-          $children[$key] = '>'.$child;
-        }
-      }
-      $children = implode('', $children);
-
+      $children = $this->getQuotedText($children);
       return $text."\n\n".$children;
     }