diff --git a/framework/Backup/lib/Horde/Backup/Writer.php b/framework/Backup/lib/Horde/Backup/Writer.php
index f70f5005f1b..59f5f9e6b72 100644
--- a/framework/Backup/lib/Horde/Backup/Writer.php
+++ b/framework/Backup/lib/Horde/Backup/Writer.php
@@ -13,6 +13,7 @@
 
 namespace Horde\Backup;
 
+use Horde_Compress_Tar as Tar;
 use Horde_Compress_Zip as Zip;
 use Horde_Pack_Driver_Json as Json;
 use Horde\Backup;
diff --git a/framework/Backup/test/Horde/Backup/BackupRestoreTest.php b/framework/Backup/test/Horde/Backup/BackupRestoreTest.php
index 7b1dd889aba..754881b1182 100644
--- a/framework/Backup/test/Horde/Backup/BackupRestoreTest.php
+++ b/framework/Backup/test/Horde/Backup/BackupRestoreTest.php
@@ -15,6 +15,7 @@
 namespace Horde\Backup;
 
 use Horde_Test_Case as TestCase;
+use Horde\Backup;
 use Horde\Backup\Writer;
 use Horde\Backup\Stub;
 
@@ -52,17 +53,14 @@ public function tearDown()
 
     public function testBackupMultipleUsers()
     {
-        $this->_createBackup();
-        $backup = new Writer($this->_temp);
-        $application = new Stub\Application();
-        $application2 = new Stub\Application2();
-        $backup->backup('calendar', $application->backup());
-        $backup->backup('addressbook', $application2->backup());
-        $backup->save();
-        $this->assertFileExists($this->_temp . '/john.zip');
-        $this->assertFileExists($this->_temp . '/jane.zip');
-        $this->_clean = false;
-        return $this->_temp;
+        return $this->_backupTest(
+            array(
+                'calendar' => new Stub\Application(),
+                'addressbook' => new Stub\Application2()
+            ),
+            null,
+            array('john', 'jane')
+        );
     }
 
     /**
@@ -70,24 +68,140 @@ public function testBackupMultipleUsers()
      */
     public function testRestoreMultipleUsers($temp)
     {
+        $this->_restoreTest(
+            $temp,
+            array(
+                'calendar' => new Stub\Application(),
+                'addressbook' => new Stub\Application2()
+            ),
+            array('jane', 'john')
+        );
+    }
+
+    public function testBackupSingleUser()
+    {
+        return $this->_backupTest(
+            array(
+                'calendar' => new Stub\Application(),
+                'addressbook' => new Stub\Application2()
+            ),
+            array('jane'),
+            array('jane')
+        );
+    }
+
+    /**
+     * @depends testBackupSingleUser
+     */
+    public function testRestoreSingleUser($temp)
+    {
+        $this->_restoreTest(
+            $temp,
+            array(
+                'calendar' => new Stub\Application(),
+                'addressbook' => new Stub\Application2()
+            ),
+            array('jane')
+        );
+    }
+
+    public function testBackupSingleApplication()
+    {
+        return $this->_backupTest(
+            array(
+                'calendar' => new Stub\Application(),
+            ),
+            null,
+            array('john', 'jane')
+        );
+    }
+
+    /**
+     * @depends testBackupSingleApplication
+     */
+    public function testRestoreSingleApplication($temp)
+    {
+        $this->_restoreTest(
+            $temp,
+            array(
+                'calendar' => new Stub\Application(),
+            ),
+            array('jane', 'john')
+        );
+    }
+
+    public function testBackupToTar()
+    {
+        return $this->_backupTest(
+            array(
+                'calendar' => new Stub\Application(),
+                'addressbook' => new Stub\Application2()
+            ),
+            null,
+            array('john', 'jane'),
+            Backup::FORMAT_TAR
+        );
+    }
+
+    /**
+     * @depends testBackupToTar
+     */
+    public function testRestoreFromTar($temp)
+    {
+        $this->markTestIncomplete();
+        $this->_restoreTest(
+            $temp,
+            array(
+                'calendar' => new Stub\Application(),
+                'addressbook' => new Stub\Application2()
+            ),
+            array('jane', 'john'),
+            Backup::FORMAT_TAR
+        );
+    }
+
+    protected function _backupTest(
+        $applications, $backupUsers, $users, $format = Backup::FORMAT_ZIP
+    )
+    {
+        $this->_createBackup();
+        $backup = new Writer($this->_temp);
+        foreach ($applications as $application => $instance) {
+            $backup->backup($application, $instance->backup($users));
+        }
+        $backup->save($format);
+        foreach ($users as $user) {
+            $this->assertFileExists(
+                $this->_temp . '/' . $user
+                    . ($format == Backup::FORMAT_ZIP ? '.zip' : '.tar')
+            );
+        }
+        $this->_clean = false;
+        return $this->_temp;
+    }
+
+    protected function _restoreTest(
+        $temp, $applications, $users, $format = Backup::FORMAT_ZIP
+    )
+    {
+        $this->_clean = true;
         $this->_temp = $temp;
         $backup = new Reader($this->_temp);
-        $users = iterator_to_array($backup->listBackups());
-        sort($users);
-        $this->assertEquals(
-            array($this->_temp . '/jane.zip', $this->_temp . '/john.zip'),
-            $users
-        );
+        $backups = iterator_to_array($backup->listBackups());
+        foreach ($users as $user) {
+            $this->assertContains(
+                $this->_temp . '/' . $user
+                    . ($format == Backup::FORMAT_ZIP ? '.zip' : '.tar'),
+                $backups
+            );
+        }
         $data = $backup->restore();
         $this->assertInternalType('array', $data);
-        $this->assertCount(2, $data);
-        $this->assertArrayHasKey('calendar', $data);
-        $this->assertArrayHasKey('addressbook', $data);
+        $this->assertCount(count($applications), $data);
+        foreach (array_keys($applications) as $application) {
+            $this->assertArrayHasKey($application, $data);
+        }
         $matrix = array();
-        $applications = array(
-            'calendar' => new Stub\Application(),
-            'addressbook' => new Stub\Application2()
-        );
         foreach ($data as $application => $collections) {
             foreach ($collections as $collection) {
                 $user = $collection->getUser();
@@ -99,37 +213,29 @@ public function testRestoreMultipleUsers($temp)
             }
         }
         ksort($matrix);
-        $this->assertEquals(
-            array(
-                'jane' => array(
-                    'calendar' => array(
-                        'events' => true
-                    ),
-                    'addressbook' => array(
-                        'addressbooks' => true,
-                        'contacts' => true,
-                    ),
+        $expected = array(
+            'jane' => array(
+                'calendar' => array(
+                    'events' => true
                 ),
-                'john' => array(
-                    'calendar' => array(
-                        'events' => true,
-                        'calendars' => true,
-                    ),
+                'addressbook' => array(
+                    'addressbooks' => true,
+                    'contacts' => true,
+                ),
+            ),
+            'john' => array(
+                'calendar' => array(
+                    'events' => true,
+                    'calendars' => true,
                 ),
             ),
-            $matrix
         );
-    }
-
-    public function testBackupSingleUser()
-    {
-    }
-
-    public function testBackupSingleApplication()
-    {
-    }
-
-    public function testBackupToTar()
-    {
+        if (!isset($applications['addressbook'])) {
+            unset($expected['jane']['addressbook']);
+        }
+        if (!in_array('john', $users)) {
+            unset($expected['john']);
+        }
+        $this->assertEquals($expected, $matrix);
     }
 }
diff --git a/framework/Backup/test/Horde/Backup/Stub/Application.php b/framework/Backup/test/Horde/Backup/Stub/Application.php
index ce4b048455f..8cd34602f48 100644
--- a/framework/Backup/test/Horde/Backup/Stub/Application.php
+++ b/framework/Backup/test/Horde/Backup/Stub/Application.php
@@ -78,10 +78,12 @@ public function backup(array $users = array())
     public function getUserBackup($user)
     {
         $backup = new User($user);
-        foreach ($this->userData[$user] as $type => $data) {
-            $backup->collections[] = new Collection(
-                new ArrayIterator($data), $user, $type
-            );
+        if (isset($this->userData[$user])) {
+            foreach ($this->userData[$user] as $type => $data) {
+                $backup->collections[] = new Collection(
+                    new ArrayIterator($data), $user, $type
+                );
+            }
         }
         return $backup;
     }