diff --git a/src/Plugin/Url/FacetUrlProcessor.php b/src/Plugin/Url/FacetUrlProcessor.php
new file mode 100644
index 0000000..3176c03
--- /dev/null
+++ b/src/Plugin/Url/FacetUrlProcessor.php
@@ -0,0 +1,222 @@
+<?php
+
+
+/**
+ * @file
+ * Contains Drupal\facetapi\Plugin\Block\FacetUrlProcessor.
+ */
+
+namespace Drupal\facetapi\Plugin\Url;
+
+/**
+ * In D7 this was the abstract class extended by all url processor plugins.
+ * This called FacetApiUrlProcessor but the name would then no longer be consistent
+ * with the FacetBlock class. Revisit the naming convention in this module?
+ *
+ * Url processor plugins provided a pluggable method of retrieving facet data.
+ * Most commonly facet data was retrieved from a query string variable via $_GET,
+ * however custom plugis could be written to retrieve data from the path as well.
+ * In addition to facet data retrieval, the url processor plugin was also
+ * responsible for building facet links and setting breadcrumb trails.
+ *
+ * Each adapter instance was associated with a single url processor plugin. The
+ * plugin was associated with the adapter via hook_facetapi_searcher_info()
+ * implementations.
+ *
+ * All functions and comments in this class have currently been copy/pasted verbatim
+ * and then tweaked to provide a skeleton that describes what the D7 version used to handle.
+ */
+
+abstract class FacetUrlProcessor {
+  /**
+   * Held the adapter that the url processor plugin was associated with.
+   *
+   * @var FacetapiAdapter
+   */
+  protected $adapter;
+
+  /**
+   * An array of facet params, usually $_GET.
+   *
+   * @var array.
+   */
+  protected $params = array();
+
+  /**
+   * The array key in FacetapiUrlProcessor::params that would contain the facet data.
+   * Also gets defined in the function parameters again.
+   * Try and keep this in one place if possible?
+   *
+   * @var string
+   */
+  protected $filterKey = 'f';
+
+  /**
+   * Constructed the FacetapiUrlProcessor object.
+   *
+   * @param FacetapiAdapter $adapter
+   *   The adapter that the url processor plugin would get associated with.
+   */
+  public function __construct(FacetapiAdapter $adapter) {
+    $this->adapter = $adapter;
+  }
+
+  /**
+   * Fetched parameters from the source, usually $_GET.
+   *
+   * This method would be invoked in FacetapiAdapter::__construct().
+   *
+   * @return array
+   *   An associative array containing the params, usually $_GET.
+   */
+  abstract public function fetchParams();
+
+  /**
+   * Normalized the array returned by FacetapiAdapter::fetchParams().
+   *
+   * When extracting data from a source such as $_GET, there are certain items
+   * that you might not want, for example the "q" or "page" keys. This method is
+   * useful for filtering those out. In addition, plugins that do not get data
+   * from $_GET can use this method to normalize the data into an associative
+   * array that closely matches the data structure of $_GET.
+   *
+   * @param array $params
+   *   An array of keyed params, usually as $_GET.
+   * @param string $filter_key
+   *   The array key in $params containing the facet data, defaults to "f".
+   *   Hardcoded to 'f' in D7 but actually it is already defined in the filterKey property
+   *   so it might make sense to no longer hardcode this in here if this function remains?
+   *
+   * @return array
+   *   An associative array containing the normalized params.
+   */
+  abstract public function normalizeParams(array $params, $filter_key = 'f');
+
+  /**
+   * Returned the query string variables for a facet item.
+   *
+   * The return array must be able to be passed as the "query" key of the
+   * options array passed as the second argument to the url() function. See
+   * http://api.drupal.org/api/drupal/includes%21common.inc/function/url/7 for
+   * more details.
+   *
+   * @param array $facet
+   *   The facet definition as returned by facetapi_facet_load().
+   * @param array $values
+   *   An array containing the item's values being added to or removed from the
+   *   query string dependent on whether or not the item is active.
+   * @param int $active
+   *   An integer flagging whether the item is active or not. 1 if the item is
+   *   active, 0 if it is not.
+   *
+   * @return array
+   *   The query string variables.
+   */
+  abstract public function getQueryString(array $facet, array $values, $active);
+
+  /**
+   * Returned the path for a facet item.
+   *
+   * This function seems to take more parameters then it needs
+   * and is not used in the standard url processor?
+   *
+   * @param array $facet
+   *   The facet definition.
+   * @param array $values
+   *   An array containing the item's values being added to or removed from the
+   *   query string dependent on whether or not the item is active.
+   * @param int $active
+   *   An integer flagging whether the item is active or not.
+   *
+   * @return string
+   *   The path of the facet.
+   */
+  public function getFacetPath(array $facet, array $values, $active) {
+    // Simply returned the search path defined by the adapter
+    return $this->adapter->getSearchPath();
+  }
+
+  /**
+   * This was used by the breadcrumb trail for active searches.
+   *
+   * This method was called by FacetapiAdapter::processFacets(), which in turn was called
+   * directly by the backend to search the chain of Facet API events.
+   *
+   * This functionality might be moved in D8 or become an option rather then
+   * remain standard functionality
+   */
+  abstract public function setBreadcrumb();
+
+  /**
+   * Used to set the normalized parameters.
+   *
+   * This method was usually called by FacetapiAdapter::setParams() and would very
+   * rarely get called directly.
+   *
+   * @param array $params
+   *   An array of normalized params hat have already been passed through
+   *   FacetapiUrlProcessor::normalizeParams().
+   * @param string $filter_key
+   *   The array key in $params containing the facet data, defaults to "f".
+   *   Hardcoded to 'f' in D7 but actually it is already defined in the filterKey property
+   *   so it might make sense to no longer hardcode this in here if this function remains?
+   *
+   * @return FacetapiUrlParser
+   *   An instance of this class.
+   */
+  public function setParams(array $params, $filter_key = 'f') {
+    $this->params = $params;
+    $this->filterKey = $filter_key;
+    if (!isset($this->params[$this->filterKey]) || !is_array($this->params[$this->filterKey])) {
+      $this->params[$this->filterKey] = array();
+    }
+    return $this;
+  }
+
+  /**
+   * A simple getter that returned the params property.
+   *
+   * @return array
+   *   An array containing the params.
+   */
+  public function getParams() {
+    return $this->params;
+  }
+
+  /**
+   * Removed an item from the $this->params array.
+   *
+   * @param int $pos
+   *   The zero-based position of the value in the source data.
+   */
+  public function removeParam($pos) {
+    unset($this->params[$this->filterKey][$pos]);
+  }
+
+  /**
+   * A simple getter that returned the filter key property.
+   *
+   * @return string
+   *   A string containing the filter key.
+   */
+  public function getFilterKey() {
+    return $this->filterKey;
+  }
+
+  /**
+   * A function that allowed for processor specific overrides to the settings form.
+   */
+  public function settingsForm(&$form, &$form_state) {
+    // Nothing to do...
+  }
+
+  /**
+   * Provided default values for the backend specific settings.
+   *
+   * @return array
+   *   The defaults keyed by setting name to value.
+   */
+  public function getDefaultSettings() {
+    return array();
+  }
+} 
\ No newline at end of file
diff --git a/src/Plugin/Url/FacetUrlProcessorStandard.php b/src/Plugin/Url/FacetUrlProcessorStandard.php
new file mode 100644
index 0000000..2d8a0b8
--- /dev/null
+++ b/src/Plugin/Url/FacetUrlProcessorStandard.php
@@ -0,0 +1,203 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\facetapi\Plugin\Block\FacetUrlProcessor.
+ */
+
+namespace Drupal\facetapi\Plugin\Url;
+
+/**
+ * In D7 this was the standard url processor
+ * This called FacetApiUrlProcessorStandard but the name would then no longer be consistent
+ * with the FacetBlock class. Revisit the naming convention in this module?
+ *
+ * This was the standard url processor plugin that retrieved facet data from the query string.
+ *
+ * This plugin retrieved facet data from $_GET, and stored all information in
+ * the "f" query string variable by default.
+ *
+ * All functions and comments in this class have currently been copy/pasted verbatim
+ * and then tweaked to provide a skeleton that describes what the D7 version used to handle.
+ */
+class FacetUrlProcessorStandard extends FacetUrlProcessor {
+  /**
+   * Stored the "limit_active_items" settings for each facet.
+   *
+   * @var array
+   */
+  protected $limitActiveItems = array();
+
+  /**
+   * Implemented FacetapiUrlProcessor::fetchParams().
+   *
+   * Used the $_GET variable as the source for facet data.
+   */
+  public function fetchParams() {
+    return $_GET;
+  }
+
+  /**
+   * Implemented FacetapiUrlProcessor::normalizeParams().
+   *
+   * Striped the "q" and "page" variables from the params array.
+   *
+   * @param array $params
+   *   An array of keyed params, usually as $_GET.
+   * @param string $filter_key
+   *   The array key in $params containing the facet data, defaults to "f".
+   *   Hardcoded to 'f' in D7 but actually it is already defined in the filterKey property
+   *   so it might make sense to no longer hardcode this in here if this function remains?
+   *
+   * @return array
+   *   An associative array containing the normalized params.
+   */
+  public function normalizeParams(array $params, $filter_key = 'f') {
+    return drupal_get_query_parameters($params, array('q', 'page'));
+  }
+
+  /**
+   * Implemented FacetapiUrlProcessor::getQueryString().
+   *
+   * @param array $facet
+   *   The facet definition as returned by facetapi_facet_load().
+   * @param array $values
+   *   An array containing the item's values being added to or removed from the
+   *   query string dependent on whether or not the item is active.
+   * @param int $active
+   *   An integer flagging whether the item is active or not. 1 if the item is
+   *   active, 0 if it is not.
+   *
+   * @return array
+   *   The query string variables.
+   */
+  public function getQueryString(array $facet, array $values, $active) {
+    $qstring = $this->params;
+    $active_items = $this->adapter->getActiveItems($facet);
+
+    // Appends to qstring if inactive, removes if active.
+    foreach ($values as $value) {
+      if ($active && isset($active_items[$value])) {
+        unset($qstring[$this->filterKey][$active_items[$value]['pos']]);
+      }
+      elseif (!$active) {
+        $field_alias = rawurlencode($facet['field alias']);
+
+        // Strips all other filters for this facet if limit option is set.
+        if ($this->limitActiveItems($facet)) {
+          foreach ($qstring[$this->filterKey] as $pos => $filter) {
+            // Refactor the if statement to best practises?
+            // (strpos($filter, $field_alias) === 0) or (strpos($filter, $field_alias) === FALSE)
+            if (0 === strpos($filter, $field_alias)) {
+              unset($qstring[$this->filterKey][$pos]);
+            }
+          }
+        }
+
+        // Adds the filter to the query string.
+        $qstring[$this->filterKey][] = $field_alias . ':' . $value;
+      }
+    }
+
+    // Removes duplicates, resets array keys and returns query string.
+    // @see http://drupal.org/node/1340528
+    $qstring[$this->filterKey] = array_values(array_unique($qstring[$this->filterKey]));
+    return array_filter($qstring);
+  }
+
+  /**
+   * Checked the facet's global "limit_active_items" settings.
+   *
+   * @param array $facet
+   *   The facet definition as returned by facetapi_facet_load().
+   *
+   * @return int
+   *   Whether or not to limit active items to one per facet.
+   */
+  public function limitActiveItems(array $facet) {
+    // If the limit property is not set for this facet
+    // retreive the settings from the facet via the adapter
+    if (!isset($this->limitActiveItems[$facet['name']])) {
+      $settings = $this->adapter->getFacetSettingsGlobal($facet);
+      $this->limitActiveItems[$facet['name']] = $settings->settings['limit_active_items'];
+    }
+    return $this->limitActiveItems[$facet['name']];
+  }
+
+  /**
+   * Implemented FacetapiUrlProcessor::setBreadcrumb().
+   */
+  public function setBreadcrumb() {
+    // Get the current breadcrumbs
+    $breadcrumb = drupal_get_breadcrumb();
+
+    // Gets search keys and active items from the adapter.
+    $keys = $this->adapter->getSearchKeys();
+    $active_items = $this->adapter->getAllActiveItems();
+
+    // Get the current menu item.
+    // Variable is not used however. Remove this line?
+    $item = menu_get_item();
+
+    // Initializes base breadcrumb query.
+    $query = $this->params;
+    unset($query[$this->filterKey]);
+
+    // Adds the current search to the query.
+    if ($keys) {
+      // The last item should be text, not a link.
+      $breadcrumb[] = $active_items ? l($keys, current_path(), array('query' => $query)) : check_plain($keys);
+    }
+
+    // Adds filters to the breadcrumb trail.
+    $last = end($active_items);
+    foreach ($active_items as $item) {
+      // Add items in the 'field_alias:value' format
+      $query[$this->filterKey][] = rawurlencode($item['field alias']) . ':' . $item['value'];
+
+      // Replaces with the mapped value.
+      $value = $this->adapter->getMappedValue($item['facets'][0], $item['value']);
+
+      // The last item should be text, not a link.
+      if ($last == $item) {
+        $breadcrumb[] = !empty($value['#html']) ? $value['#markup'] : check_plain($value['#markup']);
+      }
+      else {
+        // Appends the filter to the breadcrumb trail.
+        $breadcrumb[] = l($value['#markup'], current_path(), array('query' => $query, 'html' => !empty($value['#html'])));
+      }
+    }
+
+    // Sets the breadcrumb trail with the keys and filters.
+    drupal_set_breadcrumb($breadcrumb);
+  }
+  /**
+   * Allowed for processor specific overrides to the settings form.
+   */
+  public function settingsForm(&$form, &$form_state) {
+    $facet = $form['#facetapi']['facet'];
+    $settings = $this->adapter->getFacetSettingsGlobal($facet);
+
+    // Add the limit active item field to the form
+    $form['global']['limit_active_items'] = array(
+      '#type' => 'checkbox',
+      '#title' => t('Limit to one active item'),
+      '#prefix' => '<div class="facetapi-global-setting">',
+      '#suffix' => '</div>',
+      '#default_value' => !empty($settings->settings['limit_active_items']),
+      '#description' => t('Enabling this option allows only one item to be active at a time.'),
+    );
+  }
+
+  /**
+   * Provided default values for the backend specific settings.
+   *
+   * @return array
+   *   The defaults keyed by setting name to value. Defaults to '0'.
+   */
+  public function getDefaultSettings() {
+    return array(
+      'limit_active_items' => 0
+    );
+  }
+} 
\ No newline at end of file