diff --git a/api.module b/api.module
index 705db0a..9c77331 100644
--- a/api.module
+++ b/api.module
@@ -1267,12 +1267,25 @@ function api_block($op, $delta = NULL, $edit = array()) {
           if (user_access('access API reference') && !empty($branch)) {
             $links = array();
             $links[] = l($branch->title, 'api/' . $branch->project . '/' . $branch->branch_name);
-            $links[] = l(t('Constants'), 'api/' . $branch->project . '/constants/' . $branch->branch_name);
-            $links[] = l(t('Classes'), 'api/' . $branch->project . '/classes/' . $branch->branch_name);
-            $links[] = l(t('Files'), 'api/' . $branch->project . '/files/' . $branch->branch_name);
-            $links[] = l(t('Functions'), 'api/' . $branch->project . '/functions/' . $branch->branch_name);
-            $links[] = l(t('Globals'), 'api/' . $branch->project . '/globals/' . $branch->branch_name);
-            $links[] = l(t('Topics'), 'api/' . $branch->project . '/groups/' . $branch->branch_name);
+            $counts = api_listing_counts($branch);
+            if ($counts['constants'] > 0) {
+              $links[] = l(t('Constants'), 'api/' . $branch->project . '/constants/' . $branch->branch_name);
+            }
+            if ($counts['classes'] > 0) {
+              $links[] = l(t('Classes'), 'api/' . $branch->project . '/classes/' . $branch->branch_name);
+            }
+            if ($counts['files'] > 0) {
+              $links[] = l(t('Files'), 'api/' . $branch->project . '/files/' . $branch->branch_name);
+            }
+            if ($counts['functions'] > 0) {
+              $links[] = l(t('Functions'), 'api/' . $branch->project . '/functions/' . $branch->branch_name);
+            }
+            if ($counts['globals'] > 0) {
+              $links[] = l(t('Globals'), 'api/' . $branch->project . '/globals/' . $branch->branch_name);
+            }
+            if ($counts['groups'] > 0) {
+              $links[] = l(t('Topics'), 'api/' . $branch->project . '/groups/' . $branch->branch_name);
+            }
 
             return array(
               'subject' => t('API Navigation'),
@@ -1285,6 +1298,61 @@ function api_block($op, $delta = NULL, $edit = array()) {
 }
 
 /**
+ * Returns an array of the counts of each type of listing for a branch.
+ *
+ * @param $branch
+ *   Object representing the branch to count.
+ *
+ * @return
+ *   Associative array where the keys are the type of listing ('functions',
+ *   'classes', etc.) and the values are the count of how many there are in
+ *   that listing for the given branch.
+ */
+function api_listing_counts($branch) {
+
+  static $cached_counts = array();
+
+  // Check the cache.
+  $key = $branch->branch_name . $branch->branch_id;
+  if (isset($cached_counts[$key])) {
+    return $cached_counts[$key];
+  }
+
+  $return = array(
+    'groups' => 0,
+    'classes' => 0,
+    'functions' => 0,
+    'constants' => 0,
+    'globals' => 0,
+    'files' => 0,
+  );
+
+  // These queries mirror what is done in api_page_listing().
+  $result = db_query("SELECT COUNT(*) as num FROM {api_documentation} WHERE branch_id = %d AND object_type = 'group' GROUP BY branch_id", $branch->branch_id);
+  while ($obj = db_fetch_object($result)) {
+    $return['groups'] = $obj->num;
+    break;
+  }
+
+  $result = db_query("SELECT COUNT(*) as num FROM {api_documentation} WHERE branch_id = %d AND ( object_type = 'class' OR 'object_type' = 'interface') AND class_did = 0 GROUP BY branch_id", $branch->branch_id);
+  while ($obj = db_fetch_object($result)) {
+    $return['classes'] = $obj->num;
+    break;
+  }
+
+  foreach (array('function', 'constant', 'global', 'file') as $type) {
+    $result = db_query("SELECT COUNT(*) as num FROM {api_documentation} WHERE branch_id = %d AND object_type = '%s' AND class_did = 0 GROUP BY branch_id", $branch->branch_id, $type);
+    while ($obj = db_fetch_object($result)) {
+      $return[$type . 's'] = $obj->num;
+      break;
+    }
+  }
+
+  $cached_counts[$key] = $return;
+  return $return;
+}
+
+/**
  * Implementation of hook_filter().
  */
 function api_filter($op, $delta = 0, $format = -1, $text = '') {
@@ -1712,10 +1780,19 @@ function api_switch_project($current_branch, $url = '') {
   $links = array();
   foreach (api_get_branches() as $branch) {
     if ($branch->status && $branch->project !== $current_branch->project && !isset($links[$branch->project])) {
-      $links[$branch->project] = array(
-        'title' => $branch->project_title,
-        'href' => 'api/' . $branch->project . $url,
-      );
+      // Only make a link to this project if there are items of this type, or
+      // if the URL suffix is blank (indicating the project home page).
+      $has_items = empty($url);
+      if (!$has_items) {
+        $counts = api_listing_counts($branch);
+        $has_items = ($counts[substr($url,1)] > 0);
+      }
+      if ($has_items) {
+        $links[$branch->project] = array(
+          'title' => $branch->project_title,
+          'href' => 'api/' . $branch->project . $url,
+        );
+      }
     }
   }
   if (count($links) > 0) {
diff --git a/templates/api-branch-default-page.tpl.php b/templates/api-branch-default-page.tpl.php
index 6e551e9..09ae55d 100644
--- a/templates/api-branch-default-page.tpl.php
+++ b/templates/api-branch-default-page.tpl.php
@@ -14,14 +14,40 @@
  * - $branch->excluded_directories: The local excluded directories.
  */
 ?>
-<?php if (!empty($branch)) { ?>
+<?php if (!empty($branch)) {
+  $counts = api_listing_counts($branch);
+  if ($counts['groups'] > 0) {
+?>
   <h3><?php print l(t('Topics'), 'api/' . $branch->project . '/groups/' . $branch->branch_name); ?></h3>
   <?php print api_page_listing($branch, 'group', FALSE); ?>
+<?php
+  }
+  if ($counts['files'] > 0) {
+?>
   <h3><?php print l(t('Files'), 'api/' . $branch->project . '/files/' . $branch->branch_name); ?></h3>
+<?php
+  }
+  if ($counts['globals'] > 0) {
+?>
   <h3><?php print l(t('Globals'), 'api/' . $branch->project . '/globals/' . $branch->branch_name); ?></h3>
+<?php
+  }
+  if ($counts['constants'] > 0) {
+?>
   <h3><?php print l(t('Constants'), 'api/' . $branch->project . '/constants/' . $branch->branch_name); ?></h3>
+<?php
+  }
+  if ($counts['functions'] > 0) {
+?>
   <h3><?php print l(t('Functions'), 'api/' . $branch->project . '/functions/' . $branch->branch_name); ?></h3>
+<?php
+  }
+  if ($counts['classes'] > 0) {
+?>
   <h3><?php print l(t('Classes and Interfaces'), 'api/' . $branch->project . '/classes/' . $branch->branch_name); ?></h3>
+<?php
+  }
+?>
   <h3><?php print t('API search'); ?></h3>
    <?php print drupal_get_form('api_search_form', $branch); ?>
   <?php print api_switch_project($branch); ?>
diff --git a/tests/api_web_test.test b/tests/api_web_test.test
index cb6f43c..2631e69 100644
--- a/tests/api_web_test.test
+++ b/tests/api_web_test.test
@@ -729,3 +729,182 @@ class ApiAdminPagesTestCase extends ApiWebPagesBaseTest {
     return db_result(db_query('SELECT COUNT(*) from {api_file} WHERE modified < 100'));
   }
 }
+
+/**
+ * Provides a base class for testing multiple projects for the API module.
+ */
+class ApiMultipleProjectsBaseTest extends ApiWebPagesBaseTest {
+
+  protected $branch_info_2;
+
+  /**
+   * Overrides ApiWebPagesBaseTest::setUp().
+   *
+   * Sets up two branches in two different projects using the admin interface.
+   */
+  public function setUp() {
+    // Save the default branch for teardown.
+    $this->default_branch = variable_get('api_default_branch', NULL);
+    variable_del('api_default_branch');
+    DrupalWebTestCase::setUp('job_queue', 'grammar_parser', 'api', 'ctools');
+
+    // Set up a super-user.
+    $this->super_user = $this->drupalCreateUser(array(
+        'access API reference',
+        'administer API reference',
+        'access content',
+        'access administration pages',
+        'administer blocks',
+      ));
+    $this->drupalLogin($this->super_user);
+
+    // Create a "file" branch with the sample code, from the admin interface.
+    $this->branch_info = array(
+      'project' => 'test',
+      'branch_name' => '6',
+      'project_title' => 'Project 6',
+      'title' => 'Testing 6',
+      'status' => 1,
+      'data[directories]' => drupal_get_path('module', 'api') .'/tests/sample',
+    );
+
+    $this->drupalPost('admin/settings/api/branches/new/files',
+      $this->branch_info,
+      t('Save branch')
+    );
+
+    // Find the ID that was assigned to the function branch.
+    $branches = api_get_branches(TRUE);
+    $this_id = 0;
+    foreach ($branches as $branch) {
+      if ($branch->title == $this->branch_info['title']) {
+        $this_id = $branch->branch_id;
+        break;
+      }
+    }
+
+    // Make this the default branch.
+    $this->drupalPost('admin/settings/api/branches/list',
+      array(
+        'default_branch' => $this_id,
+      ),
+      t('Save changes')
+    );
+
+    // Create a second "file" branch in a different project, but with the same
+    // branch name.
+    $this->branch_info_2 = array(
+      'project' => 'test2',
+      'branch_name' => '6',
+      'project_title' => 'Project 2',
+      'title' => 'Testing 6',
+      'status' => 1,
+      'data[directories]' => drupal_get_path('module', 'api') .'/tests/sample2',
+    );
+
+    $this->drupalPost('admin/settings/api/branches/new/files',
+      $this->branch_info_2,
+      t('Save branch')
+    );
+
+    // Parse the code.
+    api_get_branches(TRUE);
+
+    include_once drupal_get_path('module', 'api') .'/parser.inc';
+    api_update_all_branches();
+    while (job_queue_dequeue()) { }
+    api_shutdown();
+
+    api_get_branches(TRUE);
+  }
+}
+
+/**
+ * Tests that links to empty listing pages are not created.
+ */
+class ApiEmptyPageLinksTestCase extends ApiMultipleProjectsBaseTest {
+
+  public static function getInfo() {
+    return array(
+      'name' => t('Empty listing page links'),
+      'description' => t('Tests that links to empty listing pages are not made.'),
+      'group' => 'API Module',
+    );
+  }
+
+  /**
+   * Tests that links to empty listing pages are not present.
+   */
+  function testEmptyPageLinks() {
+    // Visit the branch home page for the first project.
+    $this->drupalGet('api/' . $this->branch_info['project']);
+    // Verify that all the listing page links are there.
+    $this->assertLink('Files', 0, 'Files link is present');
+    $this->assertLink('Functions', 0, 'Functions link is present');
+    $this->assertLink('Classes and Interfaces', 0, 'Classes link is present');
+    $this->assertLink('Constants', 0, 'Constants link is present');
+    $this->assertLink('Globals', 0, 'Globals link is present');
+    $this->assertLink('Topics', 0, 'Topics link is present');
+    // Verify link to the other project is present.
+    $this->assertLink($this->branch_info_2['project_title'], 0, 'Link to other project is present');
+
+    // Visit the branch home page for the second project.
+    $this->drupalGet('api/' . $this->branch_info_2['project']);
+    // Verify that the correct listing page links are there.
+    $this->assertLink('Files', 0, 'Files link is present');
+    $this->assertLink('Functions', 0, 'Functions link is present');
+    // Verify that the listing pages that would be empty are not present.
+    $this->assertNoLink('Classes and Interfaces', 'Classes link is not present');
+    $this->assertNoLink('Constants', 'Constants link is not present');
+    $this->assertNoLink('Globals', 'Globals link is not present');
+    $this->assertNoLink('Topics', 'Topics link is not present');
+    // Verify link to the other project is present.
+    $this->assertLink($this->branch_info['project_title'], 0, 'Link to other project is present');
+
+    // Visit the Functions listing pages and verify they link to the other
+    // projects.
+    $this->drupalGet('api/' . $this->branch_info['project'] . '/functions');
+    $this->assertLink($this->branch_info_2['project_title'], 0, 'Link to other project is present');
+    $this->drupalGet('api/' . $this->branch_info_2['project'] . '/functions');
+    $this->assertLink($this->branch_info['project_title'], 0, 'Link to other project is present');
+
+    // Visit the Classes and Constants listing pages for the first project and
+    // verify there is no link to the other project.
+    $this->drupalGet('api/' . $this->branch_info['project'] . '/classes');
+    $this->assertNoLink($this->branch_info_2['project_title'], 'Link to other project is not present');
+    $this->drupalGet('api/' . $this->branch_info['project'] . '/constants');
+    $this->assertNoLink($this->branch_info_2['project_title'], 'Link to other project is not present');
+
+    // Turn on the API navigation block. Visit a function page in both
+    // projects, and verify the right links are showing in the API
+    // navigation block.
+
+    $this->drupalPost('admin/build/block/list', array(
+        'api_navigation[region]' => 'left'
+      ),
+      t('Save blocks')
+    );
+
+    // Project/branch with all possible types of items.
+    $this->drupalGet('api/' . $this->branch_info['project'] . '/sample.php/function/sample_function');
+    $this->assertText('API Navigation', 'Block title is present');
+    $this->assertLink($this->branch_info['title'], 0, 'Branch link is present');
+    $this->assertLink('Files', 0, 'Files link is present');
+    $this->assertLink('Functions', 0, 'Functions link is present');
+    $this->assertLink('Classes', 0, 'Classes link is present');
+    $this->assertLink('Constants', 0, 'Constants link is present');
+    $this->assertLink('Globals', 0, 'Globals link is present');
+    $this->assertLink('Topics', 0, 'Topics link is present');
+
+    // Project/branch with only files/functions.
+    $this->drupalGet('api/' . $this->branch_info_2['project'] . '/sample2.php/function/second_sample_function');
+    $this->assertText('API Navigation', 'Block title is present');
+    $this->assertLink($this->branch_info_2['title'], 0, 'Branch link is present');
+    $this->assertLink('Files', 0, 'Files link is present');
+    $this->assertLink('Functions', 0, 'Functions link is present');
+    $this->assertNoLink('Classes', 'Classes link is not present');
+    $this->assertNoLink('Constants', 'Constants link is not present');
+    $this->assertNoLink('Globals', 'Globals link is not present');
+    $this->assertNoLink('Topics', 'Topics link is not present');
+  }
+}
diff --git a/tests/sample2/sample2.php b/tests/sample2/sample2.php
new file mode 100644
index 0000000..928847b
--- /dev/null
+++ b/tests/sample2/sample2.php
@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * @file
+ * A sample file to make as a new project.
+ */
+
+/**
+ * A second sample function.
+ *
+ * This function links to the first sample function, with both see and link,
+ * to verify that links work across projects. The see link is at the bottom.
+ * Here is the link:
+ * @link samples Link to the samples group @endlink
+ *
+ * Here we use the sample_function(), $sample_global, and SAMPLE_CONSTANT in
+ * the text. These should all turn into links. So should a reference to the
+ * sample.php file.
+ *
+ * @see sample_function()
+ */
+function second_sample_function() {
+  // Use global variable, constant, and function from the sample project in the
+  // function body and verify that they turn into links.
+  global $sample_global;
+
+  $sample_global = SAMPLE_CONSTANT;
+
+  $foo = sample_function('a', 'b');
+}