diff --git a/wp-admin/admin-functions.php b/wp-admin/admin-functions.php
index 9c5a40c35d..1c70d199bf 100644
--- a/wp-admin/admin-functions.php
+++ b/wp-admin/admin-functions.php
@@ -490,7 +490,7 @@ function extract_from_markers($filename, $marker) {
 }
 
 function save_mod_rewrite_rules() {
-	global $is_apache;
+	global $is_apache, $wp_rewrite;
 	$home = get_settings('home');
 	if ( $home != '' && $home != get_settings('siteurl') ) {
 		$home_path = parse_url($home);
@@ -506,15 +506,13 @@ function save_mod_rewrite_rules() {
 	else
 		$writable = false;
 
-	$permalink_structure = get_settings('permalink_structure');
-
-	if ( strstr($permalink_structure, 'index.php') ) // If they're using 
+	if ($wp_rewrite->using_index_permalinks())
 		$usingpi = true;
 	else
 		$usingpi = false;
 
 	if ( $writable && !$usingpi && $is_apache ) {
-		$rules = explode("\n", mod_rewrite_rules($permalink_structure));
+		$rules = explode("\n", $wp_rewrite->mod_rewrite_rules());
 		insert_with_markers($home_path.'.htaccess', 'WordPress', $rules);
 	}
 }
diff --git a/wp-admin/options-permalink.php b/wp-admin/options-permalink.php
index dd762b317d..21447abfe0 100644
--- a/wp-admin/options-permalink.php
+++ b/wp-admin/options-permalink.php
@@ -21,22 +21,20 @@ if ( isset($_POST) ) {
 		$permalink_structure = $_POST['permalink_structure'];
 		if (! empty($permalink_structure) )
 			$permalink_structure = preg_replace('#/+#', '/', '/' . $_POST['permalink_structure']);
-		update_option('permalink_structure', $permalink_structure);
+		$wp_rewrite->set_permalink_structure($permalink_structure);
 	}
 	
 	if ( isset($_POST['category_base']) ) {
 		$category_base = $_POST['category_base'];
 		if (! empty($category_base) )
 			$category_base = preg_replace('#/+#', '/', '/' . $_POST['category_base']);
-		update_option('category_base', $category_base);
+		$wp_rewrite->set_category_base($category_base);
 	}
 }
 	
 $permalink_structure = get_settings('permalink_structure');
 $category_base = get_settings('category_base');
 
-get_date_permastruct();
-
 generate_page_rewrite_rules();
 
 if ( (!file_exists($home_path.'.htaccess') && is_writable($home_path)) || is_writable($home_path.'.htaccess') )
@@ -44,7 +42,7 @@ if ( (!file_exists($home_path.'.htaccess') && is_writable($home_path)) || is_wri
 else
 	$writable = false;
 
-if ( strstr($permalink_structure, 'index.php') ) // If they're using 
+if ($wp_rewrite->using_index_permalinks())
 	$usingpi = true;
 else
 	$usingpi = false;
@@ -106,7 +104,7 @@ save_mod_rewrite_rules();
   <p><?php _e('If your <code>.htaccess</code> was <a href="http://codex.wordpress.org/Make_a_Directory_Writable">writable</a> we could do this automatically, but it isn&#8217;t so these are the mod_rewrite rules you should have in your <code>.htaccess</code> file. Click in the field and press <kbd>CTRL + a</kbd> to select all.') ?></p>
 <form action="options-permalink.php" method="post">
    <p>
-<textarea rows="5" style="width: 98%;" name="rules"><?php echo mod_rewrite_rules($permalink_structure); ?>
+<textarea rows="5" style="width: 98%;" name="rules"><?php echo $wp_rewrite->mod_rewrite_rules(); ?>
 </textarea>
     </p>
 <?php endif; ?>
diff --git a/wp-blog-header.php b/wp-blog-header.php
index 8216bef289..1addc6be77 100644
--- a/wp-blog-header.php
+++ b/wp-blog-header.php
@@ -18,7 +18,7 @@ if ((isset($_GET['error']) && $_GET['error'] == '404') ||
 	$error = '404';
 
 	// Fetch the rewrite rules.
-	$rewrite = rewrite_rules('matches');
+	$rewrite = $wp_rewrite->wp_rewrite_rules();
 
 	if (! empty($rewrite)) {
 		$pathinfo = $_SERVER['PATH_INFO'];
diff --git a/wp-includes/classes.php b/wp-includes/classes.php
index b6617dd691..3bd29897dd 100644
--- a/wp-includes/classes.php
+++ b/wp-includes/classes.php
@@ -698,4 +698,400 @@ class retrospam_mgr {
 
 }
 
+class WP_Rewrite {
+	var $permalink_structure;
+	var $category_base;
+	var $category_structure;
+	var $date_structure;
+	var $front;
+	var $prefix = '';
+	var $index = 'index.php';
+	var $matches = '';
+	var $rewritecode = 
+		array(
+					'%year%',
+					'%monthnum%',
+					'%day%',
+					'%hour%',
+					'%minute%',
+					'%second%',
+					'%postname%',
+					'%post_id%',
+					'%category%',
+					'%author%',
+					'%pagename%',
+					'%search%'
+					);
+
+	var $rewritereplace = 
+		array(
+					'([0-9]{4})',
+					'([0-9]{1,2})',
+					'([0-9]{1,2})',
+					'([0-9]{1,2})',
+					'([0-9]{1,2})',
+					'([0-9]{1,2})',
+					'([^/]+)',
+					'([0-9]+)',
+					'(.+?)',
+					'([^/]+)',
+					'([^/]+)',
+					'(.+)'
+					);
+
+	var $queryreplace = 
+		array (
+					 'year=',
+					 'monthnum=',
+					 'day=',
+					 'hour=',
+					 'minute=',
+					 'second=',
+					 'name=',
+					 'p=',
+					 'category_name=',
+					 'author_name=',
+					 'pagename=',
+					 's='
+					 );
+
+	function using_index_permalinks() {
+    if (empty($this->permalink_structure)) {
+			return false;
+    }
+
+    // If the index is not in the permalink, we're using mod_rewrite.
+    if (preg_match('#^/*index.php#', $this->permalink_structure)) {
+      return true;
+    }
+    
+    return false;
+	}
+
+	function preg_index($number) {
+    $match_prefix = '$';
+    $match_suffix = '';
+    
+    if (! empty($this->matches)) {
+			$match_prefix = '$' . $this->matches . '['; 
+			$match_suffix = ']';
+    }        
+    
+    return "$match_prefix$number$match_suffix";        
+	}
+
+	function page_rewrite_rules() {
+		$uris = get_settings('page_uris');
+
+		$rewrite_rules = array();
+		if( is_array( $uris ) )
+			{
+				foreach ($uris as $uri => $pagename) {
+					$rewrite_rules += array($uri . '/?$' => "index.php?pagename=" . urldecode($pagename));
+				}
+			}
+
+		return $rewrite_rules;
+	}
+
+	function get_date_permastruct() {
+		if (isset($this->date_structure)) {
+			return $this->date_structure;
+		}
+
+    if (empty($this->permalink_structure)) {
+			$this->date_structure = '';
+			return false;
+		}
+		
+		// The date permalink must have year, month, and day separated by slashes.
+		$endians = array('%year%/%monthnum%/%day%', '%day%/%monthnum%/%year%', '%monthnum%/%day%/%year%');
+
+		$this->date_structure = '';
+
+		foreach ($endians as $endian) {
+			if (false !== strpos($this->permalink_structure, $endian)) {
+				$this->date_structure = $this->front . $endian;
+				break;
+			}
+		} 
+
+		if (empty($this->date_structure)) {
+			$this->date_structure = $front . '%year%/%monthnum%/%day%';
+		}
+
+		return $this->date_structure;
+	}
+
+	function get_year_permastruct() {
+		$structure = $this->get_date_permastruct($permalink_structure);
+
+		if (empty($structure)) {
+			return false;
+		}
+
+		$structure = str_replace('%monthnum%', '', $structure);
+		$structure = str_replace('%day%', '', $structure);
+
+		$structure = preg_replace('#/+#', '/', $structure);
+
+		return $structure;
+	}
+
+	function get_month_permastruct() {
+		$structure = $this->get_date_permastruct($permalink_structure);
+
+		if (empty($structure)) {
+			return false;
+		}
+
+		$structure = str_replace('%day%', '', $structure);
+
+		$structure = preg_replace('#/+#', '/', $structure);
+
+		return $structure;
+	}
+
+	function get_day_permastruct() {
+		return $this->get_date_permastruct($permalink_structure);
+	}
+
+	function get_category_permastruct() {
+		if (isset($this->category_structure)) {
+			return $this->category_structure;
+		}
+
+    if (empty($this->permalink_structure)) {
+			$this->category_structure = '';
+			return false;
+		}
+
+		if (empty($this->category_base))
+			$this->category_structure = $this->front . 'category/';
+		else
+			$this->category_structure = $this->category_base . '/';
+
+		$this->category_structure .= '%category%';
+		
+		return $this->category_structure;
+	}
+
+	function generate_rewrite_rules($permalink_structure = '', $forcomments = false) {
+		$feedregex2 = '(feed|rdf|rss|rss2|atom)/?$';
+		$feedregex = 'feed/' . $feedregex2;
+
+		$trackbackregex = 'trackback/?$';
+		$pageregex = 'page/?([0-9]{1,})/?$';
+		
+		$front = substr($permalink_structure, 0, strpos($permalink_structure, '%'));
+		preg_match_all('/%.+?%/', $permalink_structure, $tokens);
+
+		$num_tokens = count($tokens[0]);
+
+		$index = $this->index;
+		$feedindex = $index;
+		$trackbackindex = $index;
+		for ($i = 0; $i < $num_tokens; ++$i) {
+			if (0 < $i) {
+				$queries[$i] = $queries[$i - 1] . '&';
+			}
+             
+			$query_token = str_replace($this->rewritecode, $this->queryreplace, $tokens[0][$i]) . $this->preg_index($i+1);
+			$queries[$i] .= $query_token;
+		}
+
+		$structure = $permalink_structure;
+		if ($front != '/') {
+			$structure = str_replace($front, '', $structure);
+		}
+		$structure = trim($structure, '/');
+		$dirs = explode('/', $structure);
+		$num_dirs = count($dirs);
+
+		$front = preg_replace('|^/+|', '', $front);
+
+		$post_rewrite = array();
+		$struct = $front;
+		for ($j = 0; $j < $num_dirs; ++$j) {
+			$struct .= $dirs[$j] . '/';
+			$struct = ltrim($struct, '/');
+			$match = str_replace($this->rewritecode, $this->rewritereplace, $struct);
+			$num_toks = preg_match_all('/%.+?%/', $struct, $toks);
+			$query = $queries[$num_toks - 1];
+
+			$pagematch = $match . $pageregex;
+			$pagequery = $index . '?' . $query . '&paged=' . $this->preg_index($num_toks + 1);
+
+			$feedmatch = $match . $feedregex;
+			$feedquery = $feedindex . '?' . $query . '&feed=' . $this->preg_index($num_toks + 1);
+
+			$feedmatch2 = $match . $feedregex2;
+			$feedquery2 = $feedindex . '?' . $query . '&feed=' . $this->preg_index($num_toks + 1);
+
+			if ($forcomments) {
+				$feedquery .= '&withcomments=1';
+				$feedquery2 .= '&withcomments=1';
+			}
+				
+			$rewrite = array($feedmatch => $feedquery, $feedmatch2 => $feedquery2, $pagematch => $pagequery);
+
+			if ($num_toks) {
+				$post = 0;
+				if (strstr($struct, '%postname%') || strstr($struct, '%post_id%')
+						|| (strstr($struct, '%year%') &&  strstr($struct, '%monthnum%') && strstr($struct, '%day%') && strstr($struct, '%hour%') && strstr($struct, '%minute') && strstr($struct, '%second%'))) {
+					$post = 1;
+					$trackbackmatch = $match . $trackbackregex;
+					$trackbackquery = $trackbackindex . '?' . $query . '&tb=1';
+					$match = $match . '?([0-9]+)?/?$';
+					$query = $index . '?' . $query . '&page=' . $this->preg_index($num_toks + 1);
+				} else {
+					$match .= '?$';
+					$query = $index . '?' . $query;
+				}
+				        
+				$rewrite = $rewrite + array($match => $query);
+
+				if ($post) {
+					$rewrite = array($trackbackmatch => $trackbackquery) + $rewrite;
+				}
+			}
+
+			$post_rewrite = $rewrite + $post_rewrite;
+		}
+
+		return $post_rewrite;
+	}
+
+	/* rewrite_rules
+	 * Construct rewrite matches and queries from permalink structure.
+	 * Returns an associate array of matches and queries.
+	 */
+	function rewrite_rules() {
+		$rewrite = array();
+
+		if (empty($this->permalink_structure)) {
+			return $rewrite;
+		}
+
+		// Post
+		$post_rewrite = $this->generate_rewrite_rules($this->permalink_structure);
+
+		// Date
+		$date_rewrite = $this->generate_rewrite_rules($this->get_date_permastruct());
+		
+		// Root
+		$root_rewrite = $this->generate_rewrite_rules($this->prefix . '/');
+
+		// Comments
+		$comments_rewrite = $this->generate_rewrite_rules($this->prefix . 'comments', true);
+
+		// Search
+		$search_structure = $this->prefix . "search/%search%";
+		$search_rewrite = $this->generate_rewrite_rules($search_structure);
+
+		// Categories
+		$category_rewrite = $this->generate_rewrite_rules($this->get_category_permastruct());
+
+		// Authors
+		$author_structure = $this->front . 'author/%author%';
+		$author_rewrite = $this->generate_rewrite_rules($author_structure);
+
+		// Pages
+		$page_rewrite = $this->page_rewrite_rules();
+
+		// Deprecated style static pages
+		$page_structure = $this->prefix . 'site/%pagename%';
+		$old_page_rewrite = $this->generate_rewrite_rules($page_structure);
+
+		// Put them together.
+		$this->rewrite = $page_rewrite + $root_rewrite + $comments_rewrite + $old_page_rewrite + $search_rewrite + $category_rewrite + $author_rewrite + $date_rewrite + $post_rewrite;
+
+		$this->rewrite = apply_filters('rewrite_rules_array', $this->rewrite);
+		return $this->rewrite;
+	}
+
+	function wp_rewrite_rules() {
+		$this->matches = 'matches';
+		return $this->rewrite_rules();
+	}
+
+	function mod_rewrite_rules () {
+		$site_root = str_replace('http://', '', trim(get_settings('siteurl')));
+		$site_root = preg_replace('|([^/]*)(.*)|i', '$2', $site_root);
+		if ('/' != substr($site_root, -1)) $site_root = $site_root . '/';
+    
+		$home_root = str_replace('http://', '', trim(get_settings('home')));
+		$home_root = preg_replace('|([^/]*)(.*)|i', '$2', $home_root);
+		if ('/' != substr($home_root, -1)) $home_root = $home_root . '/';
+
+		$rules = "<IfModule mod_rewrite.c>\n";
+		$rules .= "RewriteEngine On\n";
+		$rules .= "RewriteBase $home_root\n";
+		$this->matches = '';
+		$rewrite = $this->rewrite_rules();
+
+		$num_rules = count($rewrite);
+		$rules .= "RewriteCond %{REQUEST_FILENAME} -f [OR]\n" .
+			"RewriteCond %{REQUEST_FILENAME} -d\n" .
+			"RewriteRule ^.*$ - [S=$num_rules]\n";
+
+		foreach ($rewrite as $match => $query) {
+			// Apache 1.3 does not support the reluctant (non-greedy) modifier.
+			$match = str_replace('.+?', '.+', $match);
+
+			// If the match is unanchored and greedy, prepend rewrite conditions
+			// to avoid infinite redirects and eclipsing of real files.
+			if ($match == '(.+)/?$' || $match == '([^/]+)/?$' ) {
+				//nada.
+			}
+
+			if (strstr($query, 'index.php')) {
+				$rules .= 'RewriteRule ^' . $match . ' ' . $home_root . $query . " [QSA,L]\n";
+			} else {
+				$rules .= 'RewriteRule ^' . $match . ' ' . $site_root . $query . " [QSA,L]\n";
+			}
+		}
+		$rules .= "</IfModule>\n";
+
+		$rules = apply_filters('rewrite_rules', $rules);
+
+		return $rules;
+	}
+
+	function init() {
+		$this->permalink_structure = get_settings('permalink_structure');
+		$this->front = substr($this->permalink_structure, 0, strpos($this->permalink_structure, '%'));		
+		$this->prefix = '';
+		if ($this->using_index_permalinks()) {
+			$this->prefix = $this->index . '/';
+		}
+		$this->category_base = get_settings('category_base');
+		unset($this->category_structure);
+		unset($this->date_structure);		
+	}
+
+	function set_permalink_structure($permalink_structure) {
+		if ($permalink_structure != $this->permalink_structure) {
+			update_option('permalink_structure', $permalink_structure);
+			$this->init();
+		}
+	}
+
+	function set_category_base($category_base) {
+		if ($category_base != $this->category_base) {
+			update_option('category_base', $category_base);
+			$this->init();
+		}
+	}
+
+	function WP_Rewrite() {
+		$this->init();
+	}
+}
+
+// Make a global instance.
+if (! isset($wp_rewrite)) {
+    $wp_rewrite = new WP_Rewrite();
+}
+
 ?>
\ No newline at end of file
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 24122b7cf6..d19a8fca31 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -1305,36 +1305,6 @@ function remove_action($tag, $function_to_remove, $priority = 10) {
 	remove_filter($tag, $function_to_remove, $priority);
 }
 
-function using_index_permalinks($permalink_structure = '') {
-    if (empty($permalink_structure)) {
-        $permalink_structure = get_settings('permalink_structure');
-	
-        if (empty($permalink_structure)) {
-            return false;
-        }
-    }
-
-    // If the index is not in the permalink, we're using mod_rewrite.
-    if (preg_match('#^/*index.php#', $permalink_structure)) {
-      return true;
-    }
-    
-    return false;
-}
-
-function preg_index($number, $matches = '') {
-    $match_prefix = '$';
-    $match_suffix = '';
-    
-    if (! empty($matches)) {
-        $match_prefix = '$' . $matches . '['; 
-        $match_suffix = ']';
-    }        
-    
-    return "$match_prefix$number$match_suffix";        
-}
-
-
 function get_page_uri($page) {
 	global $wpdb;
 	$page = $wpdb->get_row("SELECT ID, post_name, post_parent FROM $wpdb->posts WHERE ID = '$page'");
@@ -1354,325 +1324,6 @@ function get_page_uri($page) {
 	return $uri;
 }
 
-function page_rewrite_rules() {
-	$uris = get_settings('page_uris');
-
-	$rewrite_rules = array();
-        if( is_array( $uris ) )
-        {
-            foreach ($uris as $uri => $pagename) {
-							$rewrite_rules += array($uri . '/?$' => "index.php?pagename=" . urldecode($pagename));
-            }
-        }
-
-	return $rewrite_rules;
-}
-
-function get_date_permastruct($permalink_structure = '') {
-    if (empty($permalink_structure)) {
-        $permalink_structure = get_settings('permalink_structure');
-	
-        if (empty($permalink_structure)) {
-            return false;
-        }
-    }
-		
-    $front = substr($permalink_structure, 0, strpos($permalink_structure, '%'));    
-		// The date permalink must have year, month, and day separated by slashes.
-		$endians = array('%year%/%monthnum%/%day%', '%day%/%monthnum%/%year%', '%monthnum%/%day%/%year%');
-
-		$date_structure = '';
-
-		foreach ($endians as $endian) {
-			if (false !== strpos($permalink_structure, $endian)) {
-				$date_structure = $front . $endian;
-				break;
-			}
-		} 
-
-		if (empty($date_structure)) {
-				$date_structure = $front . '%year%/%monthnum%/%day%';
-		}
-
-		return $date_structure;
-}
-
-function get_year_permastruct($permalink_structure = '') {
-	$structure = get_date_permastruct($permalink_structure);
-
-	if (empty($structure)) {
-		return false;
-	}
-
-	$structure = str_replace('%monthnum%', '', $structure);
-	$structure = str_replace('%day%', '', $structure);
-
-	$structure = preg_replace('#/+#', '/', $structure);
-
-	return $structure;
-}
-
-function get_month_permastruct($permalink_structure = '') {
-	$structure = get_date_permastruct($permalink_structure);
-
-	if (empty($structure)) {
-		return false;
-	}
-
-	$structure = str_replace('%day%', '', $structure);
-
-	$structure = preg_replace('#/+#', '/', $structure);
-
-	return $structure;
-}
-
-function get_day_permastruct($permalink_structure = '') {
-	return get_date_permastruct($permalink_structure);
-}
-
-function generate_rewrite_rules($permalink_structure = '', $matches = '', $forcomments = false) {
-	$rewritecode = 
-		array(
-					'%year%',
-					'%monthnum%',
-					'%day%',
-					'%hour%',
-					'%minute%',
-					'%second%',
-					'%postname%',
-					'%post_id%',
-					'%category%',
-					'%author%',
-					'%pagename%',
-					'%search%'
-					);
-
-	$rewritereplace = 
-		array(
-					'([0-9]{4})',
-					'([0-9]{1,2})',
-					'([0-9]{1,2})',
-					'([0-9]{1,2})',
-					'([0-9]{1,2})',
-					'([0-9]{1,2})',
-					'([^/]+)',
-					'([0-9]+)',
-					'(.+?)',
-					'([^/]+)',
-					'([^/]+)',
-					'(.+)'
-					);
-
-	$queryreplace = 
-		array (
-					 'year=',
-					 'monthnum=',
-					 'day=',
-					 'hour=',
-					 'minute=',
-					 'second=',
-					 'name=',
-					 'p=',
-					 'category_name=',
-					 'author_name=',
-					 'pagename=',
-					 's='
-					 );
-
-	$feedregex2 = '(feed|rdf|rss|rss2|atom)/?$';
-	$feedregex = 'feed/' . $feedregex2;
-
-	$trackbackregex = 'trackback/?$';
-	$pageregex = 'page/?([0-9]{1,})/?$';
-
-	$front = substr($permalink_structure, 0, strpos($permalink_structure, '%'));    
-	preg_match_all('/%.+?%/', $permalink_structure, $tokens);
-
-	$num_tokens = count($tokens[0]);
-
-	$index = 'index.php';
-	$feedindex = $index;
-	$trackbackindex = $index;
-	for ($i = 0; $i < $num_tokens; ++$i) {
-		if (0 < $i) {
-			$queries[$i] = $queries[$i - 1] . '&';
-		}
-             
-		$query_token = str_replace($rewritecode, $queryreplace, $tokens[0][$i]) . preg_index($i+1, $matches);
-		$queries[$i] .= $query_token;
-	}
-
-	$structure = $permalink_structure;
-	if ($front != '/') {
-		$structure = str_replace($front, '', $structure);
-	}
-	$structure = trim($structure, '/');
-	$dirs = explode('/', $structure);
-	$num_dirs = count($dirs);
-
-	$front = preg_replace('|^/+|', '', $front);
-
-	$post_rewrite = array();
-	$struct = $front;
-	for ($j = 0; $j < $num_dirs; ++$j) {
-		$struct .= $dirs[$j] . '/';
-		$struct = ltrim($struct, '/');
-		$match = str_replace($rewritecode, $rewritereplace, $struct);
-		$num_toks = preg_match_all('/%.+?%/', $struct, $toks);
-		$query = $queries[$num_toks - 1];
-
-		$pagematch = $match . $pageregex;
-		$pagequery = $index . '?' . $query . '&paged=' . preg_index($num_toks + 1, $matches);
-
-		$feedmatch = $match . $feedregex;
-		$feedquery = $feedindex . '?' . $query . '&feed=' . preg_index($num_toks + 1, $matches);
-
-		$feedmatch2 = $match . $feedregex2;
-		$feedquery2 = $feedindex . '?' . $query . '&feed=' . preg_index($num_toks + 1, $matches);
-
-		if ($forcomments) {
-			$feedquery .= '&withcomments=1';
-			$feedquery2 .= '&withcomments=1';
-		}
-				
-		$rewrite = array($feedmatch => $feedquery, $feedmatch2 => $feedquery2, $pagematch => $pagequery);
-
-		if ($num_toks) {
-			$post = 0;
-			if (strstr($struct, '%postname%') || strstr($struct, '%post_id%')
-					|| (strstr($struct, '%year%') &&  strstr($struct, '%monthnum%') && strstr($struct, '%day%') && strstr($struct, '%hour%') && strstr($struct, '%minute') && strstr($struct, '%second%'))) {
-				$post = 1;
-				$trackbackmatch = $match . $trackbackregex;
-				$trackbackquery = $trackbackindex . '?' . $query . '&tb=1';
-				$match = $match . '?([0-9]+)?/?$';
-				$query = $index . '?' . $query . '&page=' . preg_index($num_toks + 1, $matches);
-			} else {
-				$match .= '?$';
-				$query = $index . '?' . $query;
-			}
-				        
-			$rewrite = $rewrite + array($match => $query);
-
-			if ($post) {
-				$rewrite = array($trackbackmatch => $trackbackquery) + $rewrite;
-			}
-		}
-
-		$post_rewrite = $rewrite + $post_rewrite;
-	}
-
-	return $post_rewrite;
-}
-
-/* rewrite_rules
- * Construct rewrite matches and queries from permalink structure.
- * matches - The name of the match array to use in the query strings.
- *           If empty, $1, $2, $3, etc. are used.
- * Returns an associate array of matches and queries.
- */
-function rewrite_rules($matches = '', $permalink_structure = '') {
-	$rewrite = array();
-
-	if (empty($permalink_structure)) {
-		$permalink_structure = get_settings('permalink_structure');
-        
-		if (empty($permalink_structure)) {
-			return $rewrite;
-		}
-	}
-
-	$front = substr($permalink_structure, 0, strpos($permalink_structure, '%'));
-	$index = 'index.php';
-	$prefix = '';
-	if (using_index_permalinks($permalink_structure)) {
-		$prefix = $index . '/';
-	}
-
-	// Post
-	$post_rewrite = generate_rewrite_rules($permalink_structure, $matches);
-
-	// Date
-	$date_rewrite = generate_rewrite_rules(get_date_permastruct($permalink_structure), $matches);
-		
-	// Root
-	$root_rewrite = generate_rewrite_rules($prefix . '/', $matches);
-
-	// Comments
-	$comments_rewrite = generate_rewrite_rules($prefix . 'comments', $matches, true);
-
-	// Search
-	$search_structure = $prefix . "search/%search%";
-	$search_rewrite = generate_rewrite_rules($search_structure, $matches);
-
-	// Categories
-	if ( '' == get_settings('category_base') )
-		$category_structure = $front . 'category/';
-	else
-		$category_structure = get_settings('category_base') . '/';
-
-	$category_structure = $category_structure . '%category%';
-	$category_rewrite = generate_rewrite_rules($category_structure, $matches);
-
-	// Authors
-	$author_structure = $front . 'author/%author%';
-	$author_rewrite = generate_rewrite_rules($author_structure, $matches);
-
-	// Pages
-	$page_rewrite = page_rewrite_rules();
-
-	// Deprecated style static pages
-	$page_structure = $prefix . 'site/%pagename%';
-	$old_page_rewrite = generate_rewrite_rules($page_structure, $matches);
-
-	// Put them together.
-	$rewrite = $page_rewrite + $root_rewrite + $comments_rewrite + $old_page_rewrite + $search_rewrite + $category_rewrite + $author_rewrite + $date_rewrite + $post_rewrite;
-
-	$rewrite = apply_filters('rewrite_rules_array', $rewrite);
-	return $rewrite;
-}
-
-function mod_rewrite_rules ($permalink_structure) {
-	$site_root = str_replace('http://', '', trim(get_settings('siteurl')));
-	$site_root = preg_replace('|([^/]*)(.*)|i', '$2', $site_root);
-	if ('/' != substr($site_root, -1)) $site_root = $site_root . '/';
-    
-	$home_root = str_replace('http://', '', trim(get_settings('home')));
-	$home_root = preg_replace('|([^/]*)(.*)|i', '$2', $home_root);
-	if ('/' != substr($home_root, -1)) $home_root = $home_root . '/';
-
-	$rules = "<IfModule mod_rewrite.c>\n";
-	$rules .= "RewriteEngine On\n";
-	$rules .= "RewriteBase $home_root\n";
-	$rewrite = rewrite_rules('', $permalink_structure);
-
-	$num_rules = count($rewrite);
-	$rules .= "RewriteCond %{REQUEST_FILENAME} -f [OR]\n" .
-		"RewriteCond %{REQUEST_FILENAME} -d\n" .
-		"RewriteRule ^.*$ - [S=$num_rules]\n";
-
-	foreach ($rewrite as $match => $query) {
-		// Apache 1.3 does not support the reluctant (non-greedy) modifier.
-		$match = str_replace('.+?', '.+', $match);
-
-		// If the match is unanchored and greedy, prepend rewrite conditions
-		// to avoid infinite redirects and eclipsing of real files.
-		if ($match == '(.+)/?$' || $match == '([^/]+)/?$' ) {
-			//nada.
-		}
-
-		if (strstr($query, 'index.php')) {
-			$rules .= 'RewriteRule ^' . $match . ' ' . $home_root . $query . " [QSA,L]\n";
-		} else {
-			$rules .= 'RewriteRule ^' . $match . ' ' . $site_root . $query . " [QSA,L]\n";
-		}
-	}
-	$rules .= "</IfModule>\n";
-
-	$rules = apply_filters('rewrite_rules', $rules);
-
-	return $rules;
-}
-
 function get_posts($args) {
 	global $wpdb;
 	parse_str($args, $r);
diff --git a/wp-includes/template-functions-category.php b/wp-includes/template-functions-category.php
index df9cdeef92..425e4dbeda 100644
--- a/wp-includes/template-functions-category.php
+++ b/wp-includes/template-functions-category.php
@@ -25,28 +25,22 @@ function get_the_category($id = false) {
 }
 
 function get_category_link($echo = false, $category_id, $category_nicename) {
-    global $wpdb, $post, $querystring_start, $querystring_equal, $cache_categories;
+	global $wpdb, $wp_rewrite, $post, $querystring_start, $querystring_equal, $cache_categories;
     $cat_ID = $category_id;
-    $permalink_structure = get_settings('permalink_structure');
+    $catlink = $wp_rewrite->get_category_permastruct();
     
-    if ('' == $permalink_structure) {
+    if (empty($catlink)) {
         $file = get_settings('home') . '/' . get_settings('blogfilename');
-        $link = $file.$querystring_start.'cat'.$querystring_equal.$cat_ID;
+        $catlink = $file.$querystring_start.'cat'.$querystring_equal.$cat_ID;
     } else {
-		$category_nicename = $cache_categories[$category_id]->category_nicename;
-		// Get any static stuff from the front
-        $front = substr($permalink_structure, 0, strpos($permalink_structure, '%'));
-		if ( '' == get_settings('category_base') ) :
-			$link = get_settings('home') . $front . 'category/';
-		else :
-         $link = get_settings('home') . get_settings('category_base') . '/';
-		endif;
-        if ($parent=$cache_categories[$category_id]->category_parent) $link .= get_category_parents($parent, FALSE, '/', TRUE);
-        $link .= $category_nicename . '/';
-    }
+			$category_nicename = $cache_categories[$category_id]->category_nicename;
+			if ($parent=$cache_categories[$category_id]->category_parent) $category_nicename = get_category_parents($parent, FALSE, '/', TRUE) . $category_nicename . '/';
 
-    if ($echo) echo $link;
-    return $link;
+			$catlink = str_replace('%category%', $category_nicename, $catlink);
+			$catlink = get_settings('home') . trailingslashit($catlink);
+    }
+    if ($echo) echo $catlink;
+    return $catlink;
 }
 
 function get_category_rss_link($echo = false, $category_id, $category_nicename) {
diff --git a/wp-includes/template-functions-links.php b/wp-includes/template-functions-links.php
index 2d0541b215..3c29d8411c 100644
--- a/wp-includes/template-functions-links.php
+++ b/wp-includes/template-functions-links.php
@@ -84,7 +84,7 @@ function get_permalink($id = false) {
 }
 
 function get_page_link($id = false) {
-	global $post;
+	global $post, $wp_rewrite;
 
 	if (! $id) {
 		$id = $post->ID;
@@ -94,7 +94,7 @@ function get_page_link($id = false) {
 
 	if ('' != $permalink) {
 		$link = get_page_uri($id);
-		if (using_index_permalinks()) {
+		if ($wp_rewrite->using_index_permalinks()) {
 			$link = 'index.php/' . $link;
 		}
 		$link = get_settings('home') . "/$link/";
@@ -106,49 +106,50 @@ function get_page_link($id = false) {
 }
 
 function get_year_link($year) {
-    global $querystring_start, $querystring_equal;
+	global $querystring_start, $querystring_equal, $wp_rewrite;
     if (!$year) $year = gmdate('Y', time()+(get_settings('gmt_offset') * 3600));
-		$yearlink = get_year_permastruct();
+		$yearlink = $wp_rewrite->get_year_permastruct();
     if (!empty($yearlink)) {
         $yearlink = str_replace('%year%', $year, $yearlink);
-        return get_settings('home') . $yearlink;
+        return get_settings('home') . trailingslashit($yearlink);
     } else {
         return get_settings('home') .'/'. get_settings('blogfilename') .$querystring_start.'m'.$querystring_equal.$year;
     }
 }
 
 function get_month_link($year, $month) {
-    global $querystring_start, $querystring_equal;
+    global $querystring_start, $querystring_equal, $wp_rewrite;
     if (!$year) $year = gmdate('Y', time()+(get_settings('gmt_offset') * 3600));
     if (!$month) $month = gmdate('m', time()+(get_settings('gmt_offset') * 3600));
-		$monthlink = get_month_permastruct();
+		$monthlink = $wp_rewrite->get_month_permastruct();
     if (!empty($monthlink)) {
         $monthlink = str_replace('%year%', $year, $monthlink);
         $monthlink = str_replace('%monthnum%', zeroise(intval($month), 2), $monthlink);
-        return get_settings('home') . $monthlink;
+        return get_settings('home') . trailingslashit($monthlink);
     } else {
         return get_settings('home') .'/'. get_settings('blogfilename') .$querystring_start.'m'.$querystring_equal.$year.zeroise($month, 2);
     }
 }
 
 function get_day_link($year, $month, $day) {
-    global $querystring_start, $querystring_equal;
+    global $querystring_start, $querystring_equal, $wp_rewrite;
     if (!$year) $year = gmdate('Y', time()+(get_settings('gmt_offset') * 3600));
     if (!$month) $month = gmdate('m', time()+(get_settings('gmt_offset') * 3600));
     if (!$day) $day = gmdate('j', time()+(get_settings('gmt_offset') * 3600));
 
-		$daylink = get_day_permastruct();
+		$daylink = $wp_rewrite->get_day_permastruct();
     if (!empty($daylink)) {
         $daylink = str_replace('%year%', $year, $daylink);
         $daylink = str_replace('%monthnum%', zeroise(intval($month), 2), $daylink);
         $daylink = str_replace('%day%', zeroise(intval($day), 2), $daylink);
-        return get_settings('home') . $daylink;
+        return get_settings('home') . trailingslashit($daylink);
     } else {
         return get_settings('home') .'/'. get_settings('blogfilename') .$querystring_start.'m'.$querystring_equal.$year.zeroise($month, 2).zeroise($day, 2);
     }
 }
 
 function get_feed_link($feed='rss2') {
+	global $wp_rewrite;
     $do_perma = 0;
     $feed_url = get_settings('siteurl');
     $comment_feed_url = $feed_url;
@@ -159,7 +160,7 @@ function get_feed_link($feed='rss2') {
         $feed_url = get_settings('home');
         $index = 'index.php';
         $prefix = '';
-        if (using_index_permalinks()) {
+        if ($wp_rewrite->using_index_permalinks()) {
             $feed_url .= '/' . $index;
         }
 
@@ -416,6 +417,8 @@ function next_post($format='%', $next='next post: ', $title='yes', $in_same_cat=
 }
 
 function get_pagenum_link($pagenum = 1){
+	global $wp_rewrite;
+
    $qstr = $_SERVER['REQUEST_URI'];
 
    $page_querystring = "paged"; 
@@ -453,7 +456,7 @@ function get_pagenum_link($pagenum = 1){
          $permalink = 1;
 
 	 // If it's not a path info permalink structure, trim the index.
-	 if (! using_index_permalinks()) {
+	 if (! $wp_rewrite->using_index_permalinks()) {
 	   $qstr = preg_replace("#/*" . $index . "/*#", '/', $qstr);
 	 } else {
 	   // If using path info style permalinks, make sure the index is in