diff --git a/core/includes/gettext.sketch.inc b/core/includes/gettext.sketch.inc
new file mode 100644
index 0000000..07ca70f
--- /dev/null
+++ b/core/includes/gettext.sketch.inc
@@ -0,0 +1,195 @@
+<?php
+
+/**
+ * @file
+ * Experimental "sketchy" code for gettext parsing and generating API.
+ * For a world without failures, exceptions and certainly without users ;)
+ */
+use Drupal\Core\Gettext\GettextFileInterface;
+use Drupal\Core\Gettext\PoWriter;
+use Drupal\Core\Gettext\PoReader;
+
+/**
+ * Example code to import a po file into the database.
+ *
+ * Import a po file into the Database.
+ * The file may be local, remote (via stream wrapper) or even XML.
+ * The import has a small memory footprint.
+ * The import may be split up to enable batch handling.
+ */
+$file = new GettextFileInterface('public://source.po.txt');
+gettext_import($source, $langcode);
+
+/**
+ * Imports translations from an external source into the database.
+ */
+function gettext_import($file, $langcode) {
+  // Setup a reader to fetch po formatted data from the file.
+  $source = new PoReader($file);
+
+  // Set up a (read/)write interface to write data into the database.
+  // To make the architecture more consistent this would be:
+  //   $database = new GettextDatabaseInterface();
+  //   $destination = new DatabaseWriter($database);
+  $destination = new GettextDatabase($langcode);
+
+  // Transfer meta data and translations from the file to the database.
+  gettext_transfer($source, $destination);
+}
+
+/**
+ * Example code to export translations to a po file.
+ *
+ * Export gettext data to a PO file.
+ * The file may be local, remote (via stream wrapper) or even XML.
+ * The import has a small memory footprint.
+ * The import may be split up to enable batch handling.
+ */
+$file = new GettextFileInterface('public://destination.po.txt');
+gettext_export($file, $langcode);
+
+/**
+ * Exports translations from the database to a po file.
+ */
+function gettext_export($file, $langcode) {
+  $destination = new PoWriter($file, $langcode);
+
+  // Set up a read(/write) interface to read data from the database.
+  // To make the architecture more consistent this would be:
+  //   $database = new GettextDatabaseInterface();
+  //   $destination = new DatabaseReader($database);
+  $source = new GettextDatabase($langcode);
+
+  // Transfer meta data and translations from the database to the file.
+  gettext_transfer($source, $destination);
+}
+
+/**
+ * Transfers gettext data from source to destination.
+ */
+function gettext_transfer($source, $destination, $langcode) {
+  // Transfer translations.
+  // Use batch processing if both source and destination support it and the source
+  // is large enough. If not, process in once. The threshold for batch processing
+  // could dynamically and determined by source and target. But for simplicity it is fixed.
+  if ($source->supportBatch() && $destination->supportBatch() && $source->size() > $threshold) {
+    // Transfer data in batches.
+    // Built and execute batch.
+    $batch = gettext_transfer_batch_setup($source, $destination);
+    batch_set($batch);
+  }
+  else {
+    // Transfer all translations without interruption.
+    // Process the translations one by one to keep the memory footprint low.
+    while ($translation = $source->read()) {
+      $destination->write($translation);
+    }
+  }
+}
+
+/**
+ * Set up a batch process to transfer Gettext data.
+ */
+function gettext_transfer_batch_setup($source, $destination) {
+  $batch = array(
+    'operations' => array(
+      array('gettext_transfer_batch_op', array($source, $destination)),
+    ),
+    'finished' => 'gettext_transfer_batch_finished',
+  );
+  return $batch;
+}
+
+/**
+ * Batch operation transferring gettext data.
+ *
+ * @todo Add source filter conditions (context, language(?)) as parameter.
+ */
+function gettext_transfer_batch_op($source, $destination) {
+  // Initialize sandbox for batch reading.
+  if (empty($context['sandbox'])) {
+    $context['sandbox']['transfer'] = array(
+      'chunk' => min($source->chunkSize(), $destination->chunkSize()),
+    );
+  }
+
+  // Execute one transfer cycle, which will process bite size 'chunks'.
+  $success = gettext_transfer_execute($source, $destination, $context['sandbox']['transfer']);
+
+  // After a number of cycles executing gettext_transfer_execute() the transfer
+  // is completed.
+  // See gettextapi_import_batch_op() for details.
+  if ($context['sandbox']['transfer']['finished']) {
+    $context['finished'] = 1;
+
+    if ($success) {
+      // Collect statistics from $context['sandbox']['transfer']
+      // and tell the world about what great work we did.
+    }
+  }
+}
+
+/**
+ * Batch wrap-up for gettext data transfer.
+ */
+function gettext_transfer_batch_finished($success, $results, $operations) {
+  if ($success) {
+    // Call post processing handler defined by the destination object.
+    // Can we get the callback and arguments via $results?
+    $post_process_callback = $results['post_process_callback'];
+    $arguments = $results['post_process_arguments'];
+    $post_process_callback($arguments);
+
+    // We did it, Magoo! :)
+  }
+  else {
+    // Sadly reporting where it went wrong.
+  }
+}
+
+/**
+ * Post processing for gettext language import into the database.
+ *
+ * To be called after successfull (batch) import.
+ */
+function gettext_post_process_import($langcode) {
+  // After succesfull import we refresh all affected parts of the system.
+  _locale_invalidate_js($langcode);
+  cache_clear_all('locale:', 'cache', TRUE);
+  menu_rebuild();
+}
+
+/**
+ * Transfer gettext data from source to destination in bite size chunks.
+ */
+function gettext_transfer_execute($source, $destination, &$transfer) {
+  // If transfer is not yet started we set the header data.
+  // The header (if supported) is written before the first translation is written.
+  if (!$destination->inProgress()) {
+    // Transfer translation header data.
+    $destination->setMetaData($source->getMetaData(), $langcode);
+  }
+
+  $chunk = $transfer['chunk'];
+  // Transfer translations as long as valid data is available and
+  // the bite size chunk is not yet swallowed.
+  while ($source->valid() && $chunk > 0) {
+    // Get one translation from source, write it to destination.
+    $translation = $source->read();
+    $destination->write($translation);
+    $chunk--;
+  }
+
+  // Report the percentage of completion for progress reporting.
+  // Ai, user interface. Why do we bother ;)
+  $transfer['state']['percentage_of_completion'] = $source->poc();
+
+  // Close connections when we are done and report the results.
+  if ($source->finished()) {
+    $destination->finish();
+    $transfer['finished'] = TRUE;
+  }
+
+  // Report statistics including errors and error log.
+  $transfer['result'] = $destination->statistics();
+}
diff --git a/core/lib/Drupal/Core/Gettext/BatchStateInterface.php b/core/lib/Drupal/Core/Gettext/BatchStateInterface.php
new file mode 100644
index 0000000..27ac8f9
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/BatchStateInterface.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Drupal\Core\Gettext;
+
+interface BatchStateInterface {
+  function getState();
+  function setState(array $state);
+}
diff --git a/core/lib/Drupal/Core/Gettext/BatchStreamManager.php b/core/lib/Drupal/Core/Gettext/BatchStreamManager.php
new file mode 100644
index 0000000..f1b418a
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/BatchStreamManager.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\StreamWrapper\StreamWrapperInterface;
+
+class BatchStreamManager {
+
+  private $_addition_state = array();
+  private $_stream;
+
+  /*
+   * @see stream_open
+   */
+
+  public function open($uri, $mode, $options, &$opened_url) {
+    $s = file_stream_wrapper_get_instance_by_uri($uri);
+    if ($s) {
+      $s->stream_open($uri, 'r', $options, $opened_url);
+      $this->_stream = $s;
+      $state = array(
+        'uri' => $uri,
+        'mode' => $mode,
+        'options' => $options,
+        'opened_url' => $opened_url,
+      );
+      $state += $this->_addition_state;
+      $this->_addition_state = $state;
+    }
+  }
+
+  public function getStream() {
+    return $this->_stream;
+  }
+
+  public function getBatchState() {
+    $state = $this->_addition_state;
+    if ($this->getStream()) {
+      $state['position'] = $this->getStream()->stream_tell();
+      $state['uri'] = $this->getStream()->getURI();
+    }
+    return $state;
+  }
+
+  public function setBatchState(array $state = array()) {
+    $current_state = $this->getBatchState();
+    $state += $current_state;
+    $this->_setBatchState($state);
+  }
+
+  private function _setBatchState($state) {
+    if ($this->getStream()) {
+      $this->getStream()->stream_close();
+      $this->open($state['uri'], $state['mode'], $state['options'], $opened_url);
+      $this->getStream()->stream_seek($state['position'], SEEK_SET);
+    }
+    return $this->getBatchState();
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Gettext/PODbReader.php b/core/lib/Drupal/Core/Gettext/PODbReader.php
new file mode 100644
index 0000000..23add52
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/PODbReader.php
@@ -0,0 +1,169 @@
+<?php
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\BatchStateInterface;
+use Drupal\Core\Gettext\POHeader;
+
+class PODbReader implements BatchStateInterface, PoReaderInterface {
+  /*
+   * @param $overwrite_options
+   *   An associative array indicating what data should be overwritten, if any.
+   *   - not_customized: not customized strings should be overwritten.
+   *   - customized: customized strings should be overwritten.
+   * @param $customized
+   *   (optional) Whether the strings being imported should be saved as customized.
+   *   Use LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED.
+   */
+
+  private $_options;
+  private $_langcode;
+  private $_result;
+
+  /**
+   * lid of last read record
+   *
+   * This is used to manage state.
+   * TODO: state is not working yet ... see prepared statement
+   *
+   * @see PODbReader::readItem()
+   * @see PODbReader::buildQuery()
+   */
+  private $_lid = -1;
+
+  function __construct($langcode = NULL, array $options = array()) {
+    $this->_langcode = $langcode;
+    $this->setOptions($options);
+  }
+
+  function getOptions() {
+    return $this->_options;
+  }
+
+  private function setOptions(array $options) {
+    if (!isset($options['override_options'])) {
+      $options['override_options'] = array();
+    }
+    if (!isset($options['customized'])) {
+      $options['customized'] = LOCALE_NOT_CUSTOMIZED;
+    }
+    $this->_options = array(
+      'override_options' => $options['override_options'],
+      'customized' => $options['customized'],
+    );
+  }
+
+  function setState(array $state) {
+    $this->_lid = $state['lid'];
+    $this->setOptions($state['options']);
+    $this->buildQuery();
+  }
+
+  function getState() {
+    return array(
+      'lid' => $this->_lid,
+      'options' => $this->_options,
+    );
+  }
+
+  function getHeader() {
+    return new POHeader();
+  }
+
+  /**
+   * Generates a structured array of all translated strings for the language.
+   *
+   * @param $language
+   *   Language object to generate the output for, or NULL if generating
+   *   translation template.
+   * @param $options
+   *   (optional) An associative array specifying what to include in the output:
+   *   - customized: include customized strings (if TRUE)
+   *   - uncustomized: include non-customized string (if TRUE)
+   *   - untranslated: include untranslated source strings (if TRUE)
+   *   Ignored if $language is NULL.
+   *
+   * @return
+   *   An array of translated strings that can be used to generate an export.
+   */
+  private function buildQuery() {
+    $langcode = $this->_langcode;
+    $options = $this->_options;
+
+    // Assume FALSE for all options if not provided by the API.
+    $options += array(
+      'customized' => FALSE,
+      'not_customized' => FALSE,
+      'not_translated' => FALSE,
+    );
+    if (array_sum($options) == 0) {
+      // If user asked to not include anything in the translation files,
+      // that would not make sense, so just fall back on providing a template.
+      $language = NULL;
+    }
+
+    // Build and execute query to collect source strings and translations.
+    $query = db_select('locales_source', 's');
+    if (!empty($language)) {
+      if ($options['not_translated']) {
+        // Left join to keep untranslated strings in.
+        $query->leftJoin('locales_target', 't', 's.lid = t.lid AND t.language = :language', array(':language' => $langcode));
+      }
+      else {
+        // Inner join to filter for only translations.
+        $query->innerJoin('locales_target', 't', 's.lid = t.lid AND t.language = :language', array(':language' => $langcode));
+      }
+      if ($options['customized']) {
+        if (!$options['not_customized']) {
+          // Filter for customized strings only.
+          $query->condition('t.customized', LOCALE_CUSTOMIZED);
+        }
+        // Else no filtering needed in this case.
+      }
+      else {
+        if ($options['not_customized']) {
+          // Filter for non-customized strings only.
+          $query->condition('t.customized', LOCALE_NOT_CUSTOMIZED);
+        }
+        else {
+          // Filter for strings without translation.
+          $query->isNull('t.translation');
+        }
+      }
+      $query->fields('t', array('translation'));
+    }
+    else {
+      $query->leftJoin('locales_target', 't', 's.lid = t.lid');
+    }
+    $query->fields('s', array('lid', 'source', 'context', 'location'));
+
+    // TODO: we need to order by lid
+    // This does not seem to work
+    $query->orderBy('s.lid');
+    $query->condition('s.lid', $this->_lid, '>');
+
+    $this->_result = $query->execute();
+    //echo "Executing: (lid = $this->_lid) : \n" . $this->_result->getQueryString() . "\n";
+  }
+
+  private function getResult() {
+    if (!isset($this->_result)) {
+      $this->buildQuery();
+    }
+    return $this->_result;
+  }
+
+  function readItem() {
+    $result = $this->getResult();
+    $values = $result->fetchAssoc();
+
+    if ($values) {
+      $poItem = new POItem();
+      $poItem->fromArray($values);
+      // Manage state
+      $this->_lid = $values['lid'];
+      return $poItem;
+    }
+  }
+
+}
\ No newline at end of file
diff --git a/core/lib/Drupal/Core/Gettext/PODbWriter.php b/core/lib/Drupal/Core/Gettext/PODbWriter.php
new file mode 100644
index 0000000..396c497
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/PODbWriter.php
@@ -0,0 +1,189 @@
+<?php
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\POWriter;
+
+use Drupal\Core\Gettext\POHeader;
+use Drupal\Core\Gettext\POItem;
+
+class PODbWriter implements PoWriterInterface {
+  /*
+   * @param $overwrite_options
+   *   An associative array indicating what data should be overwritten, if any.
+   *   - not_customized: not customized strings should be overwritten.
+   *   - customized: customized strings should be overwritten.
+   * @param $customized
+   *   (optional) Whether the strings being imported should be saved as customized.
+   *   Use LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED.
+   */
+
+  private $_options;
+  private $_langcode;
+
+  function __construct($langcode = NULL, array $options = array()) {
+    // TODO: decide what to do when langcode == NULL : read or write?
+    $this->_langcode = $langcode;
+    $this->setOptions($options);
+  }
+
+  function getOptions() {
+    return $this->_options;
+  }
+
+  function setOptions(array $options) {
+    if (!isset($options['override_options'])) {
+      $options['override_options'] = array();
+    }
+    if (!isset($options['customized'])) {
+      $options['customized'] = LOCALE_NOT_CUSTOMIZED;
+    }
+    $this->_options = $options;
+  }
+
+  function getHeader() {
+    return new POHeader($this->_langcode);
+  }
+
+  function writeItem(POItem $item) {
+    $report = NULL;
+    if ($item->plural) {
+      // We must iterate of plurals?
+      $item->source = join(LOCALE_PLURAL_DELIMITER, $item->source);
+      $item->translation = join(LOCALE_PLURAL_DELIMITER, $item->translation);
+    }
+    else {
+      $this->_locale_import_one_string_db($report, $this->_langcode, $item->context, $item->source, $item->translation, 'location', $this->_options['override_options'], $this->_options['customized']);
+    }
+  }
+
+  public function writeItems(PoReaderInterface $reader, $count = 10) {
+    $forever = $count == -1;
+    while (($count-- > 0 || $forever) && ($item = $reader->readItem())) {
+      $this->writeItem($item);
+    }
+  }
+
+  /**
+   * Imports one string into the database.
+   *
+   * @param $report
+   *   Report array summarizing the number of changes done in the form:
+   *   array(inserts, updates, deletes).
+   * @param $langcode
+   *   Language code to import string into.
+   * @param $context
+   *   The context of this string.
+   * @param $source
+   *   Source string.
+   * @param $translation
+   *   Translation to language specified in $langcode.
+   * @param $location
+   *   Location value to save with source string.
+   * @param $overwrite_options
+   *   An associative array indicating what data should be overwritten, if any.
+   *   - not_customized: not customized strings should be overwritten.
+   *   - customized: customized strings should be overwritten.
+   * @param $customized
+   *   (optional) Whether the strings being imported should be saved as customized.
+   *   Use LOCALE_CUSTOMIZED or LOCALE_NOT_CUSTOMIZED.
+   *
+   * @return
+   *   The string ID of the existing string modified or the new string added.
+   */
+  function _locale_import_one_string_db(&$report, $langcode, $context, $source, $translation, $location, $overwrite_options, $customized = LOCALE_NOT_CUSTOMIZED) {
+
+    // Initialize overwrite options if not set.
+    $overwrite_options += array(
+      'not_customized' => FALSE,
+      'customized' => FALSE,
+    );
+
+    // Look up the source string and any existing translation.
+    $string = db_query("SELECT s.lid, t.customized FROM {locales_source} s LEFT JOIN {locales_target} t ON s.lid = t.lid AND t.language = :language WHERE s.source = :source AND s.context = :context", array(
+      ':source' => $source,
+      ':context' => $context,
+      ':language' => $langcode,
+        ))
+        ->fetchObject();
+
+    if (!empty($translation)) {
+      // Skip this string unless it passes a check for dangerous code.
+      if (!locale_string_is_safe($translation)) {
+        watchdog('locale', 'Import of string "%string" was skipped because of disallowed or malformed HTML.', array('%string' => $translation), WATCHDOG_ERROR);
+        $report['skips']++;
+        return 0;
+      }
+      elseif (isset($string->lid)) {
+        // We have this source string saved already.
+        db_update('locales_source')
+            ->fields(array(
+              'location' => $location,
+            ))
+            ->condition('lid', $string->lid)
+            ->execute();
+
+        if (!isset($string->customized)) {
+          // No translation in this language.
+          db_insert('locales_target')
+              ->fields(array(
+                'lid' => $string->lid,
+                'language' => $langcode,
+                'translation' => $translation,
+                'customized' => $customized,
+              ))
+              ->execute();
+
+          $report['additions']++;
+        }
+        elseif ($overwrite_options[$string->customized ? 'customized' : 'not_customized']) {
+          // Translation exists, only overwrite if instructed.
+          db_update('locales_target')
+              ->fields(array(
+                'translation' => $translation,
+                'customized' => $customized,
+              ))
+              ->condition('language', $langcode)
+              ->condition('lid', $string->lid)
+              ->execute();
+
+          $report['updates']++;
+        }
+        return $string->lid;
+      }
+      else {
+        // No such source string in the database yet.
+        $lid = db_insert('locales_source')
+            ->fields(array(
+              'location' => $location,
+              'source' => $source,
+              'context' => (string) $context,
+            ))
+            ->execute();
+
+        db_insert('locales_target')
+            ->fields(array(
+              'lid' => $lid,
+              'language' => $langcode,
+              'translation' => $translation,
+              'customized' => $customized,
+            ))
+            ->execute();
+
+        $report['additions']++;
+        return $lid;
+      }
+    }
+    elseif (isset($string->lid) && isset($string->customized) && $overwrite_options[$string->customized ? 'customized' : 'not_customized']) {
+      // Empty translation, remove existing if instructed.
+      db_delete('locales_target')
+          ->condition('language', $langcode)
+          ->condition('lid', $string->lid)
+          ->execute();
+
+      $report['deletes']++;
+      return $string->lid;
+    }
+  }
+
+}
\ No newline at end of file
diff --git a/core/lib/Drupal/Core/Gettext/POHeader.php b/core/lib/Drupal/Core/Gettext/POHeader.php
new file mode 100644
index 0000000..a46030d
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/POHeader.php
@@ -0,0 +1,115 @@
+<?php
+
+namespace Drupal\Core\Gettext;
+
+/**
+ * Description of POHeader
+ *
+ * "Project-Id-Version: Drupal core (7.11)\n"
+ * "POT-Creation-Date: 2012-02-12 22:59+0000\n"
+ * "PO-Revision-Date: YYYY-mm-DD HH:MM+ZZZZ\n"
+ * "Language-Team: Catalan\n"
+ * "MIME-Version: 1.0\n"
+ * "Content-Type: text/plain; charset=utf-8\n"
+ * "Content-Transfer-Encoding: 8bit\n"
+ * "Plural-Forms: nplurals=2; plural=(n>1);\n"
+
+ * @author clemens
+ */
+class POHeader {
+
+  private $_langcode;
+  private $_projectIdVersion;
+  private $_potCreationDate;
+  private $_poRevisionDate;
+  private $_languageTeam;
+  private $_mimeVersion;
+  private $_contentType;
+  private $_contentTransferEncoding;
+  private $_pluralForms;
+  private $_authors;
+  private $_po_date;
+  private $_plurals;
+
+  public function __construct($langcode = NULL) {
+    $this->_authors = array();
+    $this->_po_date =  date("Y-m-d H:iO");
+    $this->_plurals = 'nplurals=2; plural=(n > 1);';
+    ;
+  }
+
+  static public function mapping() {
+    return array(
+      'Project-Id-Version' => '_projectIdVersion',
+      'POT-Creation-Date' => '_potCreationDate',
+      'PO-Revision-Date' => '_poRevisionDate',
+      'Language-Team' => '_languageTeam',
+      'MIME-Version' => '_mimeVersion',
+      'Content-Type' => '_contentType',
+      'Content-Transfer-Encoding' => '_contentTransferEncoding',
+      'Plural-Forms' => '_pluralForms',
+    );
+  }
+
+    /**
+   * Compile the PO header.
+   */
+  private function compileHeader() {
+    $output = '';
+
+    // Add language description and author as comment.
+    $languages = language_list();
+    $language_name = isset($languages[$this->langcode]) ? $languages[$this->langcode]->name : '';
+    $output .= '# ' . $language_name . ' translation of ' . variable_get('site_name', 'Drupal') . "\n";
+    if (!empty($this->_authors)) {
+      $output .= '# Generated by ' . implode("\n# ", $this->_authors) . "\n";
+    }
+    $output .= "#\n";
+
+    // Add the actual header information.
+    $output .= "msgid \"\"\n";
+    $output .= "msgstr \"\"\n";
+    $output .= "\"Project-Id-Version: PROJECT VERSION\\n\"\n";
+    $output .= "\"POT-Creation-Date: " . $this->_po_date . "\\n\"\n";
+    $output .= "\"PO-Revision-Date: " . $this->_po_date . "\\n\"\n";
+    $output .= "\"Last-Translator: NAME <EMAIL@ADDRESS>\\n\"\n";
+    $output .= "\"Language-Team: LANGUAGE <EMAIL@ADDRESS>\\n\"\n";
+    $output .= "\"MIME-Version: 1.0\\n\"\n";
+    $output .= "\"Content-Type: text/plain; charset=utf-8\\n\"\n";
+    $output .= "\"Content-Transfer-Encoding: 8bit\\n\"\n";
+    $output .= "\"Plural-Forms: " . $this->_plurals . "\\n\"\n";
+    $output .= "\n";
+
+    return $output;
+  }
+
+  /**
+   * Stores a given PO Header string
+   *
+   * TODO: the header string is cleaned by the parser :(
+   *   we need to accept unclean version too
+   *
+   * @param type $header
+   */
+  public function setFromString($header) {
+    $items = split("\n", $header);
+    $headers = array();
+    foreach ($items as $line) {
+      list( $key, $value) = split(':', $line, 2);
+      $headers[trim($key, ' "')] = trim($value, "\n");
+    }
+    $mapping = self::mapping();
+    foreach ($mapping as $key => $var) {
+      if (isset($headers[$key])) {
+        $this->{$var} = $headers[$key];
+      }
+    }
+  }
+
+  public function __toString() {
+    $result = $this->compileHeader() . "\n";
+    return $result;
+  }
+}
+
+?>
diff --git a/core/lib/Drupal/Core/Gettext/POItem.php b/core/lib/Drupal/Core/Gettext/POItem.php
new file mode 100644
index 0000000..ea7ced1
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/POItem.php
@@ -0,0 +1,139 @@
+<?php
+
+namespace Drupal\Core\Gettext;
+
+/**
+ * Description of POHeader
+ *
+ * "Project-Id-Version: Drupal core (7.11)\n"
+ * "POT-Creation-Date: 2012-02-12 22:59+0000\n"
+ * "PO-Revision-Date: YYYY-mm-DD HH:MM+ZZZZ\n"
+ * "Language-Team: Catalan\n"
+ * "MIME-Version: 1.0\n"
+ * "Content-Type: text/plain; charset=utf-8\n"
+ * "Content-Transfer-Encoding: 8bit\n"
+ * "Plural-Forms: nplurals=2; plural=(n>1);\n"
+
+ * @author clemens
+ */
+class POItem {
+
+  public $context;
+  public $source;
+  public $this;
+  public $plural;
+  public $comment;
+
+  static public function mapping() {
+    return array(
+      'msgctxt' => 'context',
+      'msgid' => 'source',
+      'msgstr' => 'translation',
+      '#' => 'comment',
+    );
+  }
+
+  public function fromArray(array $values = array()) {
+    foreach ($values as $key => $value) {
+      $this->{$key} = $value;
+    }
+  }
+
+  public function __toString() {
+    return $this->compileTranslation();
+  }
+
+  /**
+   * Compile PO translations strings from a translation object.
+   *
+   * Translation object consists of:
+   *   source       string (singular) or array of strings (plural)
+   *   translation  string (singular) or array of strings (plural)
+   *   plural       TRUE: source and translation are plurals
+   *   context      source context string
+   */
+  private function compileTranslation() {
+    $output = '';
+
+    // Format string context.
+    if (!empty($this->context)) {
+      $output .= 'msgctxt ' . $this->formatString($this->context);
+    }
+
+    // Format translation
+    if ($this->plural) {
+      $output .= $this->formatPlural();
+    }
+    else {
+      $output .= $this->formatSingular();
+    }
+
+    // Add one empty line to separate the translations.
+    $output .= "\n";
+
+    return $output;
+  }
+
+  /**
+   * Formats a plural translation.
+   */
+  private function formatPlural() {
+    $output = '';
+
+    // Format source strings.
+    $output .= 'msgid ' . $this->formatString($this->source[0]);
+    $output .= 'msgid_plural ' . $this->formatString($this->source[1]);
+
+    // Format translation strings.
+    $plurals = variable_get('locale_translation_plurals', array());
+    // @todo What to when $plurals[$this->langcode] is not set?
+    //       This (currently) happens if a language is created manually or importing a malformed po.
+    $nplurals = $plurals[$this->langcode]['plurals'];
+    for ($i = 0; $i < $nplurals; $i++) {
+      if (isset($this->translation[$i])) {
+        $output .= 'msgstr[' . $i . '] ' . $this->formatString($this->translation[$i]);
+      }
+      else {
+        $output .= 'msgstr[' . $i . '] ""' . "\n";
+      }
+    }
+
+    return $output;
+  }
+
+  /**
+   * Formats a singular translation.
+   */
+  private function formatSingular() {
+    $output = '';
+    $output .= 'msgid ' . $this->formatString($this->source);
+    $output .= 'msgstr ' . $this->formatString($this->translation);
+    return $output;
+  }
+
+  /**
+   * Formats a string for output on multiple lines.
+   */
+  private function formatString($string) {
+    // Escape characters for processing.
+    $string = addcslashes($string, "\0..\37\\\"");
+
+    // Always include a line break after the explicit \n line breaks from
+    // the source string. Otherwise wrap at 70 chars to accommodate the extra
+    // format overhead too.
+    $parts = explode("\n", wordwrap(str_replace('\n', "\\n\n", $string), 70, " \n"));
+
+    // Multiline string should be exported starting with a "" and newline to
+    // have all lines aligned on the same column.
+    if (count($parts) > 1) {
+      return "\"\"\n\"" . implode("\"\n\"", $parts) . "\"\n";
+    }
+    // Single line strings are output on the same line.
+    else {
+      return "\"$parts[0]\"\n";
+    }
+  }
+
+}
+
+?>
diff --git a/core/lib/Drupal/Core/Gettext/PoFileReader.php b/core/lib/Drupal/Core/Gettext/PoFileReader.php
new file mode 100644
index 0000000..c466a36
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/PoFileReader.php
@@ -0,0 +1,482 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Gettext\PoReader.
+ *
+ * TODOs
+ * - constructor needs a state
+ * - add getState
+ * - gettextInterface should have a readLine method
+ */
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\BatchStateInterface;
+use Drupal\Core\Gettext\POReader;
+
+use Drupal\Core\Gettext\POHeader;
+
+/**
+ * Defines a Gettext reader for PO format.
+ */
+class PoFileReader implements BatchStateInterface, PoReaderInterface {
+
+  /**
+   * Source line number being parsed.
+   *
+   * @var int
+   */
+  private $lineno = 0;
+
+  /**
+   * The context of the translation being parsed.
+   *
+   * @var string
+   */
+  private $context = 'COMMENT';
+
+  /**
+   * Current entry being read.
+   *
+   * @var array
+   */
+  private $current = array();
+
+  private $_uri;
+  private $_langcode;
+  private $_size;
+  private $_fd;
+
+  private $_header;
+
+  /**
+   * Implements magic function __construct().
+   */
+  public function __construct($uri, $langcode = NULL) {
+    $this->_uri = $uri;
+    $this->_langcode = $langcode;
+
+    $this->open();
+    $this->readHeader();
+  }
+
+  public function open() {
+    $this->_fd = fopen($this->_uri, 'rb');
+    $this->_size = ftell($this->_fd);
+  }
+
+  public function setState(array $state) {
+    $this->_uri = $state['uri'];
+    $this->open();
+    $this->readHeader();
+    if (isset($state['seekpos'])) {
+      fseek($this->_fd, $state['seekpos']);
+    }
+    if (isset($state['lineno'])) {
+      $this->lineno = $state['lineno'];
+    }
+  }
+
+  public function getState() {
+    return array(
+      'uri' => $this->_uri,
+      'seekpos' => ftell($this->_fd),
+      'lineno' => $this->lineno,
+    );
+  }
+
+  /**
+   * Return a translation object (singular or plural)
+   *
+   * @todo Define a translation object for this purpose?
+   *       Or use a standard class for better performance?
+   */
+  public function readItem() {
+    $translation = $this->readTranslation();
+    return $translation;
+  }
+
+  private function readTranslation() {
+    $this->latestTranslation = $this->translation;
+    $this->translation = NULL;
+    while (!$this->finished && is_null($this->translation)) {
+      $this->readLine();
+    }
+    return $this->translation;
+  }
+
+  public function getHeader() {
+    return $this->_header;
+  }
+
+  /**
+   * Reads the header from the given input stream.
+   *
+   * We need to read the optional first COMMENT
+   * Next read a MSGID and a MSGSTR
+   *
+   * TODO: is a header required?
+   */
+  private function readHeader() {
+    $translation = $this->readTranslation();
+    $header = new POHeader;
+    $header->setFromString(trim($translation->translation));
+    $this->_header = $header;
+  }
+
+  /**
+   * Reads a line from a PO file.
+   *
+   * While reading a line it's content is processed according to current
+   * context.
+   *
+   * The parser context. Can be:
+   *  - 'COMMENT' (#)
+   *  - 'MSGID' (msgid)
+   *  - 'MSGID_PLURAL' (msgid_plural)
+   *  - 'MSGCTXT' (msgctxt)
+   *  - 'MSGSTR' (msgstr or msgstr[])
+   *  - 'MSGSTR_ARR' (msgstr_arg)
+   *
+   * @return boolean FALSE or NULL
+   */
+  private function readLine() {
+    // a string or boolean FALSE
+    $line = fgets($this->_fd);
+    $this->finished = is_bool($line);
+    if (!$this->finished) {
+
+      if ($this->lineno == 0) {
+        // The first line might come with a UTF-8 BOM, which should be removed.
+        $line = str_replace("\xEF\xBB\xBF", '', $line);
+        // Current plurality for 'msgstr[]'.
+        $this->plural = 0;
+      }
+
+      $this->lineno++;
+
+      // Trim away the linefeed.
+      $line = trim(strtr($line, array("\\\n" => "")));
+
+      if (!strncmp('#', $line, 1)) {
+        // Lines starting with '#' are comments.
+
+        if ($this->context == 'COMMENT') {
+          // Already in comment token, insert the comment.
+          $this->current['#'][] = substr($line, 1);
+        }
+        elseif (($this->context == 'MSGSTR') || ($this->context == 'MSGSTR_ARR')) {
+          // We are currently in string token, close it out.
+          $this->saveOneString();
+
+          // Start a new entry for the comment.
+          $this->current = array();
+          $this->current['#'][] = substr($line, 1);
+
+          $this->context = 'COMMENT';
+          return TRUE;
+        }
+        else {
+          // A comment following any other token is a syntax error.
+          $this->log('The translation file %filename contains an error: "msgstr" was expected but not found on line %line.', $this->lineno);
+          return FALSE;
+        }
+        return;
+      }
+      elseif (!strncmp('msgid_plural', $line, 12)) {
+        // A plural form for the current message.
+
+        if ($this->context != 'MSGID') {
+          // A plural form cannot be added to anything else but the id directly.
+          $this->log('The translation file %filename contains an error: "msgid_plural" was expected but not found on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Remove 'msgid_plural' and trim away whitespace.
+        $line = trim(substr($line, 12));
+        // At this point, $line should now contain only the plural form.
+
+        $quoted = $this->parseQuoted($line);
+        if ($quoted === FALSE) {
+          // The plural form must be wrapped in quotes.
+          $this->log('The translation file %filename contains a syntax error on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Append the plural form to the current entry.
+        if (is_string($this->current['msgid'])) {
+          // The first value was stored as string. Now we know the context is
+          // plural, it is converted to array.
+          $this->current['msgid'] = array($this->current['msgid']);
+        }
+        $this->current['msgid'][] = $quoted;
+
+        $this->context = 'MSGID_PLURAL';
+        return;
+      }
+      elseif (!strncmp('msgid', $line, 5)) {
+        // Starting a new message.
+
+        if (($this->context == 'MSGSTR') || ($this->context == 'MSGSTR_ARR')) {
+          // We are currently in a message string, close it out.
+          $this->saveOneString();
+
+          // Start a new context for the id.
+          $current = array();
+        }
+        elseif ($this->context == 'MSGID') {
+          // We are currently already in the context, meaning we passed an id with no data.
+          $this->log('The translation file %filename contains an error: "msgid" is unexpected on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Remove 'msgid' and trim away whitespace.
+        $line = trim(substr($line, 5));
+        // At this point, $line should now contain only the message id.
+
+        $quoted = $this->parseQuoted($line);
+        if ($quoted === FALSE) {
+          // The message id must be wrapped in quotes.
+          $this->log('The translation file %filename contains a syntax error on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        $this->current['msgid'] = $quoted;
+        $this->context = 'MSGID';
+        return;
+      }
+      elseif (!strncmp('msgctxt', $line, 7)) {
+        // Starting a new context.
+
+        if (($this->context == 'MSGSTR') || ($this->context == 'MSGSTR_ARR')) {
+          // We are currently in a message, start a new one.
+          $this->saveOneString($current);
+          $this->current = array();
+        }
+        elseif (!empty($this->current['msgctxt'])) {
+          // A context cannot apply to another context.
+          $this->log('The translation file %filename contains an error: "msgctxt" is unexpected on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Remove 'msgctxt' and trim away whitespaces.
+        $line = trim(substr($line, 7));
+        // At this point, $line should now contain the context.
+
+        $quoted = $this->parseQuoted($line);
+        if ($quoted === FALSE) {
+          // The context string must be quoted.
+          $this->log('The translation file %filename contains a syntax error on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        $this->current['msgctxt'] = $quoted;
+
+        $this->context = 'MSGCTXT';
+        return;
+      }
+      elseif (!strncmp('msgstr[', $line, 7)) {
+        // A message string for a specific plurality.
+
+        if (($this->context != 'MSGID') && ($this->context != 'MSGCTXT') && ($this->context != 'MSGID_PLURAL') && ($this->context != 'MSGSTR_ARR')) {
+          // Message strings must come after msgid, msgxtxt, msgid_plural, or other msgstr[] entries.
+          $this->log('The translation file %filename contains an error: "msgstr[]" is unexpected on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Ensure the plurality is terminated.
+        if (strpos($line, ']') === FALSE) {
+          $this->log('The translation file %filename contains a syntax error on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Extract the plurality.
+        $frombracket = strstr($line, '[');
+        $this->plural = substr($frombracket, 1, strpos($frombracket, ']') - 1);
+
+        // Skip to the next whitespace and trim away any further whitespace, bringing $line to the message data.
+        $line = trim(strstr($line, " "));
+
+        $quoted = $this->parseQuoted($line);
+        if ($quoted === FALSE) {
+          // The string must be quoted.
+          $this->log('The translation file %filename contains a syntax error on line %line.', $this->lineno);
+          return FALSE;
+        }
+        if (!is_array($this->current['msgstr'])) {
+          $this->current['msgstr'] = array();
+        }
+
+        $this->current['msgstr'][$this->plural] = $quoted;
+
+        $this->context = 'MSGSTR_ARR';
+        return;
+      }
+      elseif (!strncmp("msgstr", $line, 6)) {
+        // A string for the an id or context.
+
+        if (($this->context != 'MSGID') && ($this->context != 'MSGCTXT')) {
+          // Strings are only valid within an id or context scope.
+          $this->log('The translation file %filename contains an error: "msgstr" is unexpected on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Remove 'msgstr' and trim away away whitespaces.
+        $line = trim(substr($line, 6));
+        // At this point, $line should now contain the message.
+
+        $quoted = $this->parseQuoted($line);
+        if ($quoted === FALSE) {
+          // The string must be quoted.
+          $this->log('The translation file %filename contains a syntax error on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        $this->current['msgstr'] = $quoted;
+
+        $this->context = 'MSGSTR';
+        return;
+      }
+      elseif ($line != '') {
+        // Anything that is not a token may be a continuation of a previous token.
+
+        $quoted = $this->parseQuoted($line);
+        if ($quoted === FALSE) {
+          // The string must be quoted.
+          $this->log('The translation file %filename contains a syntax error on line %line.', $this->lineno);
+          return FALSE;
+        }
+
+        // Append the string to the current context.
+        if (($this->context == 'MSGID') || ($this->context == 'MSGID_PLURAL')) {
+          if (is_array($this->current['msgid'])) {
+            // Add string to last array element.
+            $last_index = count($this->current['msgid']) - 1;
+            $this->current['msgid'][$last_index] .= $quoted;
+          }
+          else {
+            $this->current['msgid'] .= $quoted;
+          }
+        }
+        elseif ($this->context == 'MSGCTXT') {
+          $this->current['msgctxt'] .= $quoted;
+        }
+        elseif ($this->context == 'MSGSTR') {
+          $this->current['msgstr'] .= $quoted;
+        }
+        elseif ($this->context == 'MSGSTR_ARR') {
+          $this->current['msgstr'][$this->plural] .= $quoted;
+        }
+        else {
+          // No valid context to append to.
+          $this->log('The translation file %filename contains an error: there is an unexpected string on line %line.', $this->lineno);
+          return FALSE;
+        }
+        return;
+      }
+    }
+
+    // Empty line read or EOF of PO file, closed out the last entry.
+    if (($this->context == 'MSGSTR') || ($this->context == 'MSGSTR_ARR')) {
+      $this->saveOneString($this->current);
+    }
+    elseif ($this->context != 'COMMENT') {
+      $this->log('The translation file %filename ended unexpectedly at line %line.', $this->lineno);
+      return FALSE;
+    }
+  }
+
+  /**
+   * Sets an error message if an error occurred during locale file parsing.
+   *
+   * @param $message
+   *   The message to be translated.
+   * @param $lineno
+   *   An optional line number argument.
+   */
+  protected function log($message, $lineno = NULL) {
+    if (isset($lineno)) {
+      $vars['%line'] = $lineno;
+    }
+    $t = get_t();
+    $this->errorLog[] = $t($message, $vars);
+  }
+
+  /**
+   * Store the parsed values as translation object.
+   */
+  public function saveOneString() {
+    $value = $this->current;
+    $plural = FALSE;
+
+    $comments = empty($value['#']) ? $this->shortenComments($value['#']) : '';
+
+    if (is_array($value['msgstr'])) {
+      // Sort plural variants by their form index.
+      ksort($value['msgstr']);
+      $plural = TRUE;
+    }
+
+    $translation = new POItem;
+    $translation->context = isset($value['msgctxt']) ? $value['msgctxt'] : '';
+    $translation->source = $value['msgid'];
+    $translation->translation = $value['msgstr'];
+    $translation->plural = $plural;
+    $translation->comment = $comments;
+
+    $this->translation = $translation;
+
+    $this->context = 'COMMENT';
+  }
+
+  /**
+   * Parses a string in quotes.
+   *
+   * @param $string
+   *   A string specified with enclosing quotes.
+   *
+   * @return
+   *   The string parsed from inside the quotes.
+   */
+  function parseQuoted($string) {
+    if (substr($string, 0, 1) != substr($string, -1, 1)) {
+      return FALSE;   // Start and end quotes must be the same
+    }
+    $quote = substr($string, 0, 1);
+    $string = substr($string, 1, -1);
+    if ($quote == '"') {        // Double quotes: strip slashes
+      return stripcslashes($string);
+    }
+    elseif ($quote == "'") {  // Simple quote: return as-is
+      return $string;
+    }
+    else {
+      return FALSE;             // Unrecognized quote
+    }
+  }
+
+  /**
+   * Generates a short, one-string version of the passed comment array.
+   *
+   * @param $comment
+   *   An array of strings containing a comment.
+   *
+   * @return
+   *   Short one-string version of the comment.
+   */
+  private function shortenComments($comments) {
+    $comm = '';
+    while (count($comment)) {
+      $test = $comm . substr(array_shift($comment), 1) . ', ';
+      if (strlen($comm) < 130) {
+        $comm = $test;
+      }
+      else {
+        break;
+      }
+    }
+    return trim(substr($comm, 0, -2));
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Gettext/PoFileWriter.php b/core/lib/Drupal/Core/Gettext/PoFileWriter.php
new file mode 100644
index 0000000..d9090de
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/PoFileWriter.php
@@ -0,0 +1,84 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Gettext\PoWriter.
+ */
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\POHeader;
+use Drupal\Core\Gettext\BatchStateInterface;
+
+/**
+ * Defines a Gettext writer.
+ */
+class PoFileWriter implements BatchStateInterface {
+
+  private $_uri;
+  private $_header;
+  private $_fd;
+  private $_seekpos;
+  private $_open = FALSE;
+
+  function __construct($uri, POHeader $header) {
+    $this->_uri = $uri;
+    $this->_header = $header;
+    $this->open();
+  }
+
+  private function open() {
+    // Open in append mode
+    $this->_fd = fopen($this->_uri, 'a');
+    // If file is new position == 0
+    $this->_seekpos = ftell($this->_fd);
+    if ($this->_seekpos == 0) {
+      $this->writeHeader();
+    }
+    else {
+      $reader = new PoFileReader($this->uri);
+      $this->_header = $reader->getHeader();
+    }
+  }
+
+  public function close() {
+    fclose($this->_fd);
+  }
+
+  public function setState(array $state) {
+    $this->_uri = $state['uri'];
+    $this->open();
+  }
+
+  public function getState() {
+    return array(
+      'uri' => $this->_uri,
+      'seekpos' => ftell($this->_fd),
+    );
+  }
+
+  private function write($data) {
+    $result = fputs($this->_fd, $data);
+    if ($result === FALSE) {
+      // TODO: better context for message
+      throw new \Exception("Unable to write data : " . substr($data, 0, 20));
+    }
+    $this->_seekpos = ftell($this->_fd);
+  }
+
+  private function writeHeader() {
+    $this->write($this->_header);
+  }
+
+  public function writeItem(POItem $item) {
+    $this->write($item);
+  }
+
+  public function writeItems($reader, $count = 10) {
+    $forever = $count == -1;
+    while (($count-- > 0 || $forever) && ($item = $reader->readItem())) {
+      $this->writeItem($item);
+    }
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Gettext/PoReaderInterface.php b/core/lib/Drupal/Core/Gettext/PoReaderInterface.php
new file mode 100644
index 0000000..03b725b
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/PoReaderInterface.php
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Gettext\PoReader.
+ *
+ * TODOs
+ * - constructor needs a state
+ * - add getState
+ * - gettextInterface should have a readLine method
+ */
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\Reader;
+use Drupal\Core\Gettext\POHeader;
+
+/**
+ * Defines a Gettext reader for PO format.
+ */
+interface PoReaderInterface {
+
+  function readItem();
+}
diff --git a/core/lib/Drupal/Core/Gettext/PoWriterInterface.php b/core/lib/Drupal/Core/Gettext/PoWriterInterface.php
new file mode 100644
index 0000000..80db733
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/PoWriterInterface.php
@@ -0,0 +1,20 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Gettext\PoWriter.
+ */
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\POHeader;
+use Drupal\Core\Gettext\POItem;
+
+/**
+ * Defines a Gettext writer.
+ */
+interface PoWriterInterface {
+  function writeItem(POItem $item);
+  function writeItems(PoReaderInterface $reader, $count = 10);
+  function getHeader();
+}
diff --git a/core/lib/Drupal/Core/Gettext/Reader.php b/core/lib/Drupal/Core/Gettext/Reader.php
new file mode 100644
index 0000000..93f441f
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/Reader.php
@@ -0,0 +1,155 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Gettext\Reader.
+ */
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\GettextInterface;
+
+/**
+ * Defines a Gettext reader.
+ *
+ * @todo Or implement this as traversable/Iterator ?
+ */
+abstract class Reader {
+
+  protected $gettextInterface;    // Gettext Data interface
+  protected $metaData = array();  // Gettext meta data e.g. language, plural formula.
+  protected $biteSize = 100;      // Default bite size
+  protected $langcode = '';       // Language code of the translation data.
+  //protected $language;            // Language object of selected language.
+  protected $index = 0;           // Pointer where we are reading the content, in number of translations.
+  protected $sourceSize;          // Calculated or estimated size of the data source in number of translations.
+  protected $inProgress = FALSE;  // Boolean indicating the data connection is open and transfer may have started.
+  //protected $valid = FALSE;       // Boolean indicating valid data is available. // @todo Needed?
+  protected $finished = FALSE;    // Boolean indicating the last record has been read;
+  protected $filter = array();    // Array of filter arguments used to filter translations being read.
+  protected $errorLog = array();  // Log of parsing errors.
+
+  /**
+   * Implements magic function __construct().
+   */
+  public function __construct(GettextInterface $interface) {
+    $this->gettextInterface = $interface;
+  }
+
+  /**
+   * Implements magic function __destruct().
+   */
+  public function __destruct() {
+    $this->gettextInterface->close();
+  }
+
+  /**
+   * Return a translation object (singular or plural)
+   *
+   * @todo Define a translation object for this purpose?
+   *       Or use a standard class for better performance?
+   */
+  public function read() {
+  }
+
+  /**
+   * Return header/meta data (date, plural formula, etc.)
+   */
+  public function getMetaData() {
+    return $this->metaData;
+  }
+
+  /**
+   * Return TRUE if the file is opened or the transfer has started.
+   */
+  public function inProgress() {
+    return $this->inProgress;
+  }
+
+  /**
+   * Return the name of an error callback function
+   */
+  public function errorCallback() {
+    return '';
+  }
+
+  /**
+   * Return arguments for an error callback function
+   */
+  public function errorArguments() {
+    return array();
+  }
+
+  /**
+   * Return the name of a post processing callback function
+   */
+  public function postProcessCallback() {
+    return '';
+  }
+
+  /**
+   * Return arguments for a post processing callback function
+   */
+  public function postProcessArguments() {
+    return array();
+  }
+
+  /**
+   * Return the calculated or estimated size in number of translations. Zero for unknown. To be generated without opening the connection. e.g. use file size not number of lines.
+   */
+  public function size() {
+    return $this->sourceSize;
+  }
+
+  /**
+   * Return a bite size. Based on experience and size to be transfered within a reasonable time. Size in number of source/translations pairs. e.g. database records in locales_source or locales_target tables. A set of plural's are counted as one.
+   */
+  public function biteSize() {
+    return $this->bite_size;
+  }
+
+  /**
+   * Accept a set of data filter arguments: Language, Context
+   */
+  public function setFilter($arguments) {
+    $this->filter = $arguments;
+  }
+
+  /**
+   * Return Is valid. Valid data is available, not EOF, no errors, etc.
+   */
+  public function valid() {
+    return $this->valid;
+  }
+
+  /**
+   * Get percentage of completion (read)
+   */
+  public function poc() {
+    if (!$this->$inProgress) {
+      return 0;
+    }
+    if ($this->finished) {
+      return 1;
+    }
+    // If reading is not finished, we limit the percentage to max. 95%
+    // Percentages above 100% are a result of low estimate of source size and
+    // will be suppressed.
+    return min(0.95, $this->index/$this->sourceSize);
+  }
+
+  /**
+   * Return syntax errors
+   */
+  public function getLog($category = NULL) {
+    return $this->errorLog;
+  }
+
+  /**
+   * Internal: log syntax errors
+   */
+  protected function log($line, $message) {
+    $this->errorLog[$line] = $message;
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Gettext/Writer.php b/core/lib/Drupal/Core/Gettext/Writer.php
new file mode 100644
index 0000000..34c0c3d
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/Writer.php
@@ -0,0 +1,172 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Gettext\Writer.
+ */
+
+namespace Drupal\Core\Gettext;
+
+use Drupal\Core\Gettext\GettextInterface;
+
+/**
+ * Defines a Gettext writer.
+ */
+abstract class Writer {
+
+  protected $gettextInterface;    // Gettext Data interface
+  protected $metaData = array();  // Gettext meta data e.g. language, plural formula.
+  protected $biteSize = 100;      // Default bite size
+  protected $langcode = '';       // Language code of the translation data.
+  protected $language;            // Language object of selected language.
+  protected $inProgress = FALSE;  // Boolean indicating the data connection is open and transfer may have started.
+  protected $valid = FALSE;       // Boolean indicating valid data is available. // @todo Needed?
+  protected $writeMode = '';      // Whether to replace or skip existing translations when writing translation.
+  protected $resultsAdded = 0;    // Number of translations added.
+  protected $resultsReplaced = 0; // Number of translations replaced.
+  protected $resultsIgnored = 0;  // Number of translations Ignored.
+  protected $resultsError = 0;    // Number of strings containing invalid html;
+  protected $errorLog = array();  // Log of parsing errors.
+
+  /**
+   * Implements magic function __construct().
+   */
+
+  public function __construct(GettextInterface $interface, $langcode) {
+    $this->gettextInterface = $interface;
+    $this->langcode = $langcode;
+
+    $languages = language_list();
+    if (isset($languages[$langcode])) {
+      $this->language = $languages[$langcode];
+    }
+    else {
+      // @todo throw error: Unknown language code.
+    }
+
+    // Set default meta data.
+    $this->metaData = array(
+      'authors' => array(),
+      'po_date' => date("Y-m-d H:iO"),
+      'plurals' => 'nplurals=2; plural=(n > 1);',
+    );
+  }
+
+  /**
+   * Implements magic function __destruct().
+   */
+  public function __destruct() {
+    $this->gettextInterface->close();
+  }
+
+  /**
+   * Write translation string (singular or plural)
+   *
+   * @todo Define a translation object for this purpose?
+   *       Or use a standard class for better performance?
+   */
+  public function write($translation) {
+
+  }
+
+  /**
+   * Set header/meta data (date, plural formula, etc.)
+   */
+  public function setMetaData(array $data) {
+    $this->metaData = array_merge($this->metaData, $data);
+  }
+
+  /**
+   * Return TRUE if the file is opened or the transfer has started.
+   */
+  public function inProgress() {
+    return $this->inProgress;
+  }
+
+  /**
+   * Return the name of an error callback function
+   */
+  public function errorCallback() {
+    return '';
+  }
+
+  /**
+   * Return arguments for an error callback function
+   */
+  public function errorArguments() {
+    return array();
+  }
+
+  /**
+   * Return the name of a post processing callback function
+   */
+  public function postProcessCallback() {
+    return '';
+  }
+
+  /**
+   * Return arguments for a post processing callback function
+   */
+  public function postProcessArguments() {
+    return array();
+  }
+
+  /**
+   * Return a bite size. Based on experience and size to be transfered within a reasonable time. Size in number of source/translations pairs. e.g. database records in locales_source or locales_target tables. A set of plural's are counted as one.
+   */
+  public function biteSize() {
+    return $this->bite_size;
+  }
+
+  /**
+   * Return the language code as defined by the data (e.g. po header). Use language filter (see below) as fallback.
+   */
+  public function langcode() {
+    return $this->langcode;
+  }
+
+  /**
+   * Accept write mode argument (replace, keep changes, skip existing)
+   *
+   * @todo Move this to __constructor()?
+   */
+  public function setWriteMode($mode) {
+    $this->writeMode = $mode;
+  }
+
+  /**
+   * Return Is valid. Valid data is available, not EOF, no errors, etc.
+   *
+   * @todo Needed for Writer?
+   */
+  public function valid() {
+    return $this->valid;
+  }
+
+  /**
+   * Get statistics (added, replaced, ignored, error, error log)
+   */
+  public function statistics() {
+    return array(
+      'added' => $this->resultsAdded,
+      'replaced' => $this->resultsReplaced,
+      'ignored' => $this->resultsIgnored,
+      'error' => $this->resultsError,
+    );
+  }
+
+  /**
+   * Return syntax errors
+   */
+  public function getLog($category = NULL) {
+    return $this->errorLog;
+  }
+
+  /**
+   * Internal: log syntax errors
+   */
+  protected function log($line, $message) {
+    $this->errorLog[$line] = $message;
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Gettext/testGettext.php b/core/lib/Drupal/Core/Gettext/testGettext.php
new file mode 100644
index 0000000..6b9ce3f
--- /dev/null
+++ b/core/lib/Drupal/Core/Gettext/testGettext.php
@@ -0,0 +1,522 @@
+<?php
+
+$cmd = __FILE__;
+$_SERVER['HTTP_HOST'] = 'default';
+$_SERVER['PHP_SELF'] = '/index.php';
+$_SERVER['REMOTE_ADDR'] = '127.0.0.1';
+$_SERVER['SERVER_SOFTWARE'] = NULL;
+$_SERVER['REQUEST_METHOD'] = 'GET';
+$_SERVER['QUERY_STRING'] = '';
+$_SERVER['PHP_SELF'] = $_SERVER['REQUEST_URI'] = '/';
+$_SERVER['HTTP_USER_AGENT'] = 'console';
+
+define('DRUPAL_ROOT', getcwd());
+
+include_once DRUPAL_ROOT . '/core/includes/bootstrap.inc';
+drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
+
+/**
+ * Run this like:
+ * drush @drupal.d8 php-script core/lib/Drupal/Core/Gettext/testGettext.php
+ */
+use Drupal\Core\Gettext\GettextFileInterface;
+use Drupal\Core\Gettext\BatchStreamManager;
+use Drupal\Core\Gettext\POHeader;
+use Drupal\Core\Gettext\PODbWriter;
+use Drupal\Core\Gettext\PODbReader;
+use Drupal\Core\Gettext\PoFileReader;
+use Drupal\Core\Gettext\PoFileWriter;
+
+function logLine($string, $type = '-') {
+  echo str_repeat($type, 50) . "\n";
+  echo str_repeat(" ", 0) . $string . "\n";
+  if ($type != '-') {
+    echo str_repeat('-', 50) . "\n";
+  }
+}
+
+/**
+ * Creates a test PO stucture
+ *
+ * TODO: the object structure is for .po so we miss the .pot format
+ *
+ * @param type $langcode
+ * @return array of objects
+ */
+function gettext_struct($langcode = 'nl') {
+  $translations = array(
+    (object) array(
+      'source' => 'home',
+      'translation' => 'thuis',
+      'plural' => 0,
+      'context' => '',
+    ),
+    (object) array(
+      'source' => 'delete',
+      'translation' => 'verwijderen',
+      'plural' => 0,
+      'context' => '',
+    ),
+    (object) array(
+      'source' => array('1 day', '@count days'),
+      'translation' => array('1 dag', '@count dagen'),
+      'plural' => 1,
+      'context' => '',
+    ),
+  );
+
+  return array(
+    'langcode' => $langcode,
+    'items' => $translations,
+  );
+}
+
+/**
+ * A simple writer of the pot structure
+ *
+ * TODO: the header is not specified enough.
+ *
+ * @param type $uri
+ */
+function testGettextWrite($uri) {
+  $struct = gettext_struct();
+
+  $file = new GettextFileInterface($uri);
+  $target = new PoWriter($file, $langcode);
+  $header = array(
+    'authors' => array('me', 'you'),
+    'po_date' => date("Y-m-d H:iO"),
+    'plurals' => 'nplurals=2; plural=(n > 1);',
+  );
+  $target->setMetaData($header, $struct['langcode']);
+
+  $translations = $struct['items'];
+  foreach ($translations as $translation) {
+    $target->write($translation);
+  }
+}
+
+/**
+ * Processes a File into a database
+ *
+ * @param type $uri
+ * @param type $dbwriter
+ * @param type $type
+ */
+function testProcessFileToDb($uri, $dbwriter, $type = 'po') {
+  // Producer
+  $producer = testFileToStruct($uri, $type);
+  // Consumer
+  $dbwriter->batchProcess($producer, $type);
+}
+
+function testWriteToPublic() {
+  logLine(__FUNCTION__, '=');
+  // Write into public
+  $file = 'public://text-file.txt.po';
+  testGettextWrite($file);
+  echo file_get_contents($file);
+  echo "\n\n";
+
+  $uri = 'public://infinite-text-file.txt.po';
+  testInfiniteProducer($uri, 10);
+
+  echo file_get_contents($uri);
+}
+
+function testBatchStreamManager() {
+  logLine(__FUNCTION__, '=');
+  $uri = 'public://infinite-text-file.txt.po';
+  echo file_get_contents($uri);
+
+  echo "Creating new BatchStreamManager()\n";
+  $bsm = new BatchStreamManager();
+  echo "  state:\n";
+  print_r($bsm->getBatchState());
+
+  echo "Opening stream $uri\n";
+// $uri, $mode, $options, &$opened_url
+  $bsm->open($uri, 'r', 0, $full_path);
+  echo "  state:\n";
+  print_r($bsm->getBatchState());
+
+  $my_s = $bsm->getStream();
+  echo "Reading 10 bytes\n";
+  $bytes = $my_s->stream_read(10);
+  echo "  Bytes read: '$bytes'\n";
+
+  echo "  state:\n";
+  print_r($bsm->getBatchState());
+
+  echo "Moving to position 50\n";
+  $state = $bsm->getBatchState();
+  $state['position'] = 50;
+  $bsm->setBatchState($state);
+  $my_s = $bsm->getStream();
+
+  echo "  state:\n";
+  print_r($bsm->getBatchState());
+
+  echo "Reading 15 bytes\n";
+  $bytes = $my_s->stream_read(15);
+  echo "  Bytes read: '$bytes'\n";
+
+  echo "  state:\n";
+  print_r($bsm->getBatchState());
+}
+
+function getReadStream($uri) {
+  logLine(__FUNCTION__, '=');
+  $s = new GettextFileInterface($uri);
+  return $s;
+}
+
+function testPoReader() {
+  logLine(__FUNCTION__, '=');
+
+  $uri = 'public://test.po.txt';
+
+  logLine("Reading : $uri", '=');
+  logLine("File contents first 500 bytes");
+  $contents = file_get_contents($uri);
+  echo substr($contents, 0, 500) . "\n";
+
+  logLine("Using PoFileReader");
+  $reader = new PoFileReader($uri);
+
+  echo $reader->getHeader();
+  print_r($translation);
+
+  $i = 0;
+  while (($item = $reader->readItem()) && $i++ < 4) {
+    printItem($item, $i);
+  }
+}
+
+function testHeader() {
+  logLine(__FUNCTION__, '=');
+  $h = new POHeader();
+
+  echo "----------------\n";
+  $h->setFromString('');
+  echo "empty header\n";
+  echo $h;
+
+  echo "----------------\n";
+  $h->setFromString('"Project-Id-Version: ' . __FILE__ . '\n"');
+  echo "-- one item -- \n";
+  echo $h;
+}
+
+function testFileToDb() {
+  logLine(__FUNCTION__, '=');
+  $uri = 'public://test.po.txt';
+  logLine("Reading : $uri");
+  logLine("File contents first 500 bytes");
+  $contents = file_get_contents($uri);
+  echo substr($contents, 0, 500) . "\n";
+
+  logLine("Using new classes");
+  $reader = new PoFileReader($uri);
+
+  $writer = new PODbWriter('ca');
+
+  printItem($reader->getHeader());
+
+  $i = 0;
+  while (($item = $reader->readItem()) && $i < 4) {
+    printItem($item, $i++);
+    $writer->writeItem($item);
+  }
+}
+
+function testDbDump() {
+  logLine(__FUNCTION__, '=');
+  $reader = new PODbReader('en');
+  echo $reader->getHeader() . "\n";
+
+  $i = 0;
+  while (($item = $reader->readItem()) && $i < 4) {
+    printItem($item, $i++);
+  }
+
+  echo "Saving state to simulate a batch\n";
+  $state = $reader->getState();
+
+  echo "Create a new PODbReader so simulate a batch\n";
+  $reader = new PODbReader('en');
+
+  // Set the state
+  $reader->setState($state);
+  $i = 0;
+  while (($item = $reader->readItem()) && $i < 4) {
+    printItem($item, $i++);
+  }
+}
+
+function printItem($item, $context = 0) {
+  logLine(__FUNCTION__, '=');
+  if ($item) {
+    logLine("$context : $item->lid");
+    print_r($item);
+  }
+}
+
+function readItem($reader, $context = 0) {
+  $item = $reader->readItem();
+  if ($item) {
+    printItem($item);
+  }
+}
+
+function dumpState($state) {
+  logLine(__FUNCTION__, '=');
+  print_r($state);
+}
+
+function testPOFileReader($uri) {
+  logLine(__FUNCTION__, '=');
+
+  $reader = new \Drupal\Core\Gettext\PoFileReader($uri);
+  dumpState($reader->getState());
+  echo $reader->getHeader() . "\n";
+  dumpState($reader->getState());
+  $i = 0;
+  while (($item = readItem($reader)) && $i < 4) {
+    printItem($item, $i++);
+  }
+  dumpState($reader->getState());
+}
+
+function getLanguages($langcode = NULL) {
+  logLine(__FUNCTION__, '=');
+  if (!is_null($langcode)) {
+    return array($langcode);
+  }
+  return array(
+    'nl',
+    'ar',
+    'ca',
+    'en', // does not exists on d.o (should it be?)
+    'NOP', // does really not exists on d.o
+  );
+}
+
+function getRemoteUris($langcode = NULL) {
+  logLine(__FUNCTION__, '=');
+  $langcodes = getLanguages($langcode);
+  $uris = array();
+  foreach ($langcodes as $langcode) {
+    $uri = "http://ftp.drupal.org/files/translations/7.x/drupal/drupal-7.11.$langcode.po";
+    $uris[$langcode] = $uri;
+  }
+  return $uris;
+}
+
+function getPublicUri($name, $langcode) {
+  logLine(__FUNCTION__, '=');
+  $result = "public://$name-$langcode.po";
+  logLine($result);
+  return $result;
+}
+
+function getRemoteUri($langcode) {
+  $uris = getRemoteUris($langcode);
+  return $uris[$langcode];
+}
+
+function testRemotePOPumper() {
+  logLine(__FUNCTION__, '=');
+  $uris = getRemoteUris();
+  foreach ($uris as $langcode => $uri) {
+    logLine("langcode: $langcode");
+    $reader = new PoFileReader($uri);
+    $writer = new PODbWriter($langcode);
+    $writer->writeItems($reader, 10);
+  }
+}
+
+function testPOFileWriter() {
+  logLine(__FUNCTION__, '=');
+  $src = "http://ftp.drupal.org/files/translations/7.x/drupal/drupal-7.11.ar.po";
+
+  $reader = new \Drupal\Core\Gettext\PoFileReader($src);
+  $header = $reader->getHeader();
+
+  $dst = 'public://drupal-7.11.ar.po';
+  zapUri($dst);
+  $writer = new PoFileWriter($dst, $header);
+
+  $i = 0;
+  while (($item = $reader->readItem()) && $i < 4) {
+    printItem($item, $i);
+    $i++;
+    $writer->writeItem($item);
+    dumpState($writer->getState());
+  }
+
+  $writer->close();
+}
+
+function testDbToFile() {
+  logLine(__FUNCTION__, '=');
+  $reader = new PODbReader('ca');
+
+  $dst = 'public://drupal-7.11.dummy.po';
+  $header = $reader->getHeader();
+
+  $writer = new Drupal\Core\Gettext\PoFileWriter($dst, $header);
+
+  $i = 0;
+  while (($item = $reader->readItem()) && $i < 4) {
+    printItem($item, $i);
+    $i++;
+    $writer->writeItem($item);
+    dumpState($writer->getState());
+  }
+
+  $writer->writeItems($reader, 10);
+
+  $writer->close();
+}
+
+function testBatchSimulation() {
+  logLine(__FUNCTION__, '=');
+
+  // Grab first langcode
+  $uris = getRemoteUris();
+  $langcode = key($uris);
+  $src = current($uris);
+
+  logLine("Opening $langcode : $src");
+  $reader = new PoFileReader($src);
+  $header = $reader->getHeader();
+  logLine($header);
+
+  $dst = getPublicUri(__FUNCTION__, $langcode);
+
+  zapUri($dst);
+  logLine("Writing $langcode : $dst");
+  $writer = new PoFileWriter($dst, $header);
+
+  logLine('Written header only', '=');
+  echo file_get_contents($dst);
+
+  processN($writer, $reader, 2);
+
+  dumpFileContents($dst);
+
+  $state = $reader->getState();
+  dumpState($state);
+
+  logLine('Replacing reader', '=');
+  $reader = new PoFileReader($src);
+
+  logLine('setting state back');
+  $reader->setState($state);
+  dumpState($state);
+
+  processN($writer, $reader, 3);
+  $reader->setState($state);
+  dumpState($state);
+
+  dumpFileContents($dst);
+}
+
+function testDBReaderState() {
+  $langcode = 'nl';
+  $reader = new PODbReader($langcode);
+  logLine("Init PODbReader", '=');
+  $state = $reader->getState();
+  dumpState($state);
+
+
+  $uri = getPublicUri(__FUNCTION__, $langcode);
+  zapUri($uri);
+  $writer = new PoFileWriter($uri, $reader->getHeader());
+
+  processN($writer, $reader, 4);
+
+  logLine("Read some", '=');
+  $state = $reader->getState();
+  dumpState($state);
+
+  $reader = new PODbReader($langcode);
+  $reader->setState($state);
+  processN($writer, $reader, 4);
+  $state = $reader->getState();
+  dumpState($state);
+
+  logLine("File contents from $uri", '=');
+  echo file_get_contents($uri);
+}
+
+function zapUri($uri) {
+  logLine("Truncate $uri", '=');
+  ftruncate(fopen($uri, 'w'));
+}
+
+function processN($writer, $reader, $count = 10) {
+  if ($count == -1) {
+    logLine("processing items: __ALL__");
+  }
+  else {
+    logLine("processing items: $count");
+  }
+  $writer->writeItems($reader, $count);
+}
+
+function dumpFileContents($uri) {
+  logLine("Written: $uri", '=');
+  echo file_get_contents($uri);
+}
+
+function pumpAround($langcode) {
+  logLine(__FUNCTION__, '=');
+  $uri = getRemoteUri($langcode);
+
+  logLine("Reading from $uri");
+  $reader = new PoFileReader($uri, $langcode);
+  $header = $reader->getHeader();
+
+  $uri = getPublicUri(__FUNCTION__ . '-remote', $langcode);
+  zapUri($uri);
+  logLine("Writing to $uri");
+  $writer = new PoFileWriter($uri, $header);
+
+  processN($writer, $reader, -1);
+
+  logLine("Reading from $uri");
+  $reader = new PoFileReader($uri, $langcode);
+  logLine("Writing to DB");
+  $writer = new PODbWriter($langcode);
+
+  processN($writer, $reader, -1);
+
+
+  logLine("Reading from DB");
+  $reader = new PODbReader($langcode);
+  $header = $reader->getHeader();
+
+  $uri = getPublicUri(__FUNCTION__ . '-db', $langcode);
+  zapUri($uri);
+  logLine("Writing to $uri");
+  $writer = new PoFileWriter($uri, $header);
+  processN($writer, $reader, -1);
+}
+
+testDBReaderState();
+testBatchStreamManager();
+testPoReader();
+testHeader();
+testFileToDb();
+testDbDump();
+testPOFileReader();
+testPOFileWriter();
+testDbToFile();
+testRemotePOPumper();
+testBatchSimulation();
+
+pumpAround('ar');
+pumpAround('ca');
+pumpAround('nl');
diff --git a/core/modules/simpletest/tests/gettext.test b/core/modules/simpletest/tests/gettext.test
new file mode 100644
index 0000000..0bd968e
--- /dev/null
+++ b/core/modules/simpletest/tests/gettext.test
@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * @file
+ * Provides unit tests for gettext.inc.
+ */
+
+use Drupal\Core\Gettext;
+
+/**
+ * Unit tests for the graph handling features.
+ */
+class GettextUnitTest extends DrupalUnitTestCase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Gettext',
+      'description' => 'Gettext handling unit tests.',
+      'group' => 'System',
+    );
+  }
+
+  function setUp() {
+    parent::setUp();
+  }
+
+  /**
+   * Test loading a small Po.
+   */
+  function testLoadSmallPo() { 
+  }
+}
+
diff --git a/core/vendor/Symfony/Component/Config b/core/vendor/Symfony/Component/Config
new file mode 120000
index 0000000..3421ac7
--- /dev/null
+++ b/core/vendor/Symfony/Component/Config
@@ -0,0 +1 @@
+../../../../../symfony/src/Symfony/Component/Config
\ No newline at end of file
diff --git a/core/vendor/Symfony/Component/Translation b/core/vendor/Symfony/Component/Translation
new file mode 120000
index 0000000..5b0c441
--- /dev/null
+++ b/core/vendor/Symfony/Component/Translation
@@ -0,0 +1 @@
+../../../../../symfony/src/Symfony/Component/Translation
\ No newline at end of file