diff --git a/lib/Alchemy/Phrasea/Core.php b/lib/Alchemy/Phrasea/Core.php
index 77ca90737c..a35fe63540 100644
--- a/lib/Alchemy/Phrasea/Core.php
+++ b/lib/Alchemy/Phrasea/Core.php
@@ -24,7 +24,13 @@ require_once __DIR__ . '/../../vendor/Silex/vendor/pimple/lib/Pimple.php';
 class Core extends \Pimple
 {
 
-  public function __construct($isDev = false)
+  /**
+   *
+   * @var Core\Configuration
+   */
+  private $conf;
+  
+  public function __construct($env)
   {
 
     /**
@@ -32,14 +38,18 @@ class Core extends \Pimple
      */
     static::initAutoloads();
 
+    
+    $this->conf = new Core\Configuration($env);
+    
     $this['Version'] = $this->share(function()
             {
               return new Core\Version();
             });
-
-    $this['EM'] = $this->share(function()
+     
+    $conf = $this->conf;
+    $this['EM'] = $this->share(function() use ($conf)
             {
-              $doctrine = new Core\Service\Doctrine();
+              $doctrine = new Core\Service\Doctrine($conf->getDoctrineConf());
               return $doctrine->getEntityManager();
             });
 
@@ -91,6 +101,20 @@ class Core extends \Pimple
     return;
   }
 
+  private function init()
+  {
+    if ($this->conf->debug)
+    {
+      ini_set('display_errors', 1);
+      error_reporting(E_ALL);
+      \Symfony\Component\HttpKernel\Debug\ErrorHandler::register();
+    }
+    else
+    {
+      ini_set('display_errors', 0);
+    }
+  }
+
   /**
    *
    * @return Request 
@@ -291,4 +315,14 @@ class Core extends \Pimple
     return;
   }
 
+
+  public function getEnv()
+  {
+    return $this->env;
+  }
+
+  public function isDebug()
+  {
+    return $this->conf->debug;
+  }
 }
diff --git a/lib/Alchemy/Phrasea/Core/Configuration.php b/lib/Alchemy/Phrasea/Core/Configuration.php
new file mode 100644
index 0000000000..c4e9150cdc
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Core/Configuration.php
@@ -0,0 +1,203 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2010 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Alchemy\Phrasea\Core;
+
+/**
+ *
+ * @package
+ * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
+ * @link        www.phraseanet.com
+ */
+class Configuration
+{
+
+  public $debug = false;
+  
+  protected $dbConf;
+  protected $installed;
+  
+
+  public function __construct($envName)
+  {
+    $specifications = new Configuration\PhraseaConfiguration();
+    $parser = new Configuration\Parser\Yaml();
+    
+    $handler = new Configuration\EnvironnementHandler($specifications, $parser);
+    
+    $configuration = $handler->handle($envName);
+    
+    var_dump($configuration);
+    
+    exit;
+  }
+
+  public function getMainConfigFileName()
+  {
+    return 'config';
+  }
+
+  /**
+   *
+   * @return \SplFileObject
+   */
+  public function getMainConfigFile()
+  {
+    return $this->mainConfigFile;
+  }
+
+  public function getDoctrineConf()
+  {
+    return (array) $this->dbConf;
+  }
+
+  public function isInstalled()
+  {
+    return $this->installed;
+  }
+
+  private function loadEnvironnments($env)
+  {
+    $filename = $this->loadFileName($env);
+
+    if (!is_file($filename))
+      throw new \InvalidArgumentException(sprintf('Config file %s do not exist', $filename));
+
+    $envConf = \Symfony\Component\Yaml\Yaml::parse($filename);
+
+    $this->envsConf[] = $envConf;
+
+    if (isset($envConf["extends"]))
+    {
+      $this->loadEnvironnments($envConf["extends"]);
+    }
+    else
+    {
+      return;
+    }
+  }
+
+  private function substituteEnvConfToMainConf(Array $mainConf)
+  {
+    foreach (array_reverse($this->envsConf) as $env)
+    {
+      $this->conf = array_replace_recursive($this->conf, $env);
+    }
+
+    $this->conf = array_replace_recursive($mainConf, $this->conf);
+  }
+
+  private function loadFileName($env = 'main')
+  {
+    if ('main' === $env)
+    {
+      return sprintf('%s/%s.yml', $this->configFilePath, $this->getMainConfigFileName());
+    }
+    else
+    {
+      return sprintf('%s/%s_%s.yml', $this->configFilePath, $this->getMainConfigFileName(), $env);
+    }
+  }
+
+  private function getNoneReplacedPath()
+  {
+    return array(
+        array('doctrine', 'dbal')
+    );
+  }
+
+  private function process($env)
+  {
+    $mainConf = \Symfony\Component\Yaml\Yaml::parse($this->loadFileName());
+
+    $this->loadEnvironnments($env);
+
+    $this->substituteEnvConfToMainConf($mainConf);
+
+    $path = array();
+
+    $excludedPath = $pathToProcess = $this->getNoneReplacedPath();
+
+    $confToChange = $this->conf;
+
+    foreach (array_reverse($this->envsConf) as $conf)
+    {
+      foreach ($pathToProcess as $key => $thePath)
+      {
+        $replaceValue = $this->getDataPath($conf, $thePath);
+        
+        if (null !== $replaceValue)
+        {
+          $map = function($item, $key) use (&$confToChange, $replaceValue, &$map, &$path, $thePath)
+                  {
+                      if (count(array_diff($path, $thePath) === 0))
+                      {
+                        
+                        $path[] = $key;
+                        $replace = function(&$searchArray, $path, $value, $depth = 0) use (&$replace)
+                                {
+                                  foreach ($searchArray as $k => $v)
+                                  {
+                                    if ($k === $path[$depth])
+                                    {
+                                      array_shift($path);
+                                      if (is_array($v) && count($path) !== 0)
+                                      {
+                                        $replace(&$searchArray[$k], $path, $value, $depth++);
+                                      }
+                                      else
+                                      {
+                                        $searchArray[$k] = $value;
+                                      }
+                                    }
+                                  }
+                                };
+                        $replace($confToChange, $path, $replaceValue);
+                      }
+                      elseif (is_array($item))
+                      {
+                        $path[] = $key;
+                        array_walk($item, $map);
+                      }
+                  };
+           
+          array_walk($this->conf, $map);
+          unset($pathToProcess[$key]);
+        }
+      }
+    }
+  }
+
+  public function getDataPath(Array $data, Array $path)
+  {
+    $found = true;
+
+    for ($x = 0; ($x < count($path) && $found); $x++)
+    {
+      $key = $path[$x];
+
+      if (isset($data[$key]))
+      {
+        $data = $data[$key];
+      }
+      else
+      {
+        $found = false;
+      }
+    }
+
+    if ($found)
+      return $data;
+    else
+      return null;
+  }
+
+}
\ No newline at end of file
diff --git a/lib/Alchemy/Phrasea/Core/Configuration/ConfigurationSpecification.php b/lib/Alchemy/Phrasea/Core/Configuration/ConfigurationSpecification.php
new file mode 100644
index 0000000000..e921894e97
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Core/Configuration/ConfigurationSpecification.php
@@ -0,0 +1,79 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2010 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Alchemy\Phrasea\Core\Configuration;
+
+/**
+ *
+ * @package
+ * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
+ * @link        www.phraseanet.com
+ */
+
+interface ConfigurationSpecification
+{
+  /**
+   * Keywords to detect extended file
+   */
+  const EXTENDED_KEYWORD = 'extends';
+  
+  /**
+   * Return an array of paths that CAN'T be extended by ONLY one or more of their value
+   * but must be fully replaced with new values
+   * 
+   * example:
+   * array(array('PATH', 'TO', 'MY', 'SCOPE1', array('SCOPE2')
+   * 
+   * So $extendedConf['PATH']['TO']['MY']['SCOPE'] will fully replace
+   *    $mainConf['PATH']['TO']['MY']['SCOPE'];
+   *  
+   * @return Array
+   */
+  public function getNonExtendablePath();
+  
+  /**
+   * Return the configuration file from an environnment name
+   * 
+   * @return \SplFileObject
+   */
+  public function getConfFileFromEnvName($name);
+  
+  /**
+   * Return the path to the configuration file
+   * 
+   * @return string
+   */
+  public function getConfigurationFilePath();
+  
+  /**
+   * Return the configurationFile extension
+   * 
+   * @return string
+   */
+  public function getConfFileExtension();
+  
+   /**
+   * Check wether the environnement $env extends another one
+   * 
+   * @param type $env
+   * @return boolean 
+   */
+  public function isExtended(Array $env);
+  
+  /**
+   * Return the extends environnement name null if extends nothing
+   * 
+   * @param Array an environnement
+   * @return mixed|null
+   */
+  public function getExtendedEnvName(Array $env);
+  
+}
\ No newline at end of file
diff --git a/lib/Alchemy/Phrasea/Core/Configuration/EnvironnementHandler.php b/lib/Alchemy/Phrasea/Core/Configuration/EnvironnementHandler.php
new file mode 100644
index 0000000000..0700c17abb
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Core/Configuration/EnvironnementHandler.php
@@ -0,0 +1,204 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2010 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Alchemy\Phrasea\Core\Configuration;
+
+use \Symfony\Component\Yaml\Yaml;
+
+/**
+ *
+ * @package
+ * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
+ * @link        www.phraseanet.com
+ */
+class EnvironnementHandler
+{
+  /**
+   * Configuration file specification interface
+   * @var ConfigurationSpecification 
+   */
+  protected $confSpecification;
+
+  /**
+   * A file parser interface 
+   * @var Parser\ParserInterface
+   */
+  protected $parser;
+
+  public function __construct(ConfigurationSpecification $configSpec, Parser\ParserInterface $parser)
+  {
+    $this->confSpecification = $configSpec;
+    $this->parser = $parser;
+  }
+
+  /**
+   * Stacks all envrironnement in $env that extends the loaded configuration file
+   * 
+   * @param SplFileObject $file File of the current loaded config file
+   * @param array $envs A stack of conf environnments
+   * @return array 
+   */
+  private function retrieveExtendedEnvFromFile(\SplFileObject $file, Array $envs = array())
+  {
+    $env = $this->parser->parse($file);
+
+    //stack current env to allEnvs 
+    $allEnvs[] = $env;
+
+    //check if the loaded environnement extends another configuration file
+    if ($this->confSpecification->isExtended($env))
+    {
+      try
+      {
+        //get extended environnement name
+        $envName = $this->confSpecification->getExtendedEnvName($env);
+        //get extended configuration file
+        $file = $this->confSpecification->getConfFileFromEnvName($envName);
+        //recurse
+        $this->retrieveExtendedEnvFromFile($file, $allEnvs);
+      }
+      catch (\Exception $e)
+      {
+        throw \Exception(sprintf("filename %s not found", $file->getPathname()));
+      }
+    }
+
+    return $allEnvs;
+  }
+
+  /**
+   * Get the value of a specified data path 
+   * 
+   * @param array $data The array where the data are stored
+   * @param array $path The Path as an  array example : array('path', 'to', 'my', 'value')
+   * @return mixed 
+   */
+  private function getDataPath(Array $data, Array $path)
+  {
+    $found = true;
+
+    for ($x = 0; ($x < count($path) && $found); $x++)
+    {
+      $key = $path[$x];
+
+      if (isset($data[$key]))
+      {
+        $data = $data[$key];
+      }
+      else
+      {
+        $found = false;
+      }
+    }
+
+    return $found ? $data : null;
+  }
+
+  /**
+   * Handle the configuration process and return the final configuration
+   * 
+   * @param strinig $name the name of the loaded environnement
+   * @return Array
+   */
+  public function handle($name)
+  {
+
+    //get the corresepondant file
+    $file = $this->confSpecification->getConfFileFromEnvName($name);
+
+    //get all extended configuration from current env
+    $allEnvs = $this->retrieveExtendedEnvFromFile($file);
+
+    //Last env is the main one
+    $mainEnv = array_pop($allEnvs);
+
+    $excludedPath = $pathToprocess = $this->confSpecification->getNonExtendablePath();
+
+    //at least 2 envs and one path to process
+    if (count($allEnvs) >= 1 && count($excludedPath) >= 1)
+    {
+      foreach ($allEnvs as $currentEnv) // run trought environnements
+      {
+        foreach ($pathToprocess as $kpath => $processedPath) //run throught path
+        {
+          $valueToReplace = $this->getDataPath($currentEnv, $processedPath); //retrive the value to replace
+
+          if (null !== $valueToReplace)
+          {
+
+            // reset current path
+            $currentPath = array();
+
+            //callback to iterate over the main conf environnement and replace value from extended file
+            $map = function($item, $key) use (&$mainEnv, $valueToReplace, &$map, &$currentPath, $processedPath)
+                    {
+                      if (count(array_diff($processedPath, $currentPath)) === 0) // current path and processed path match
+                      {
+                        /**
+                         * Replace current value of the $currentpath in $searchArray by $value
+                         */
+                        $replace = function(&$searchArray, $currentPath, $value) use (&$replace)
+                                {
+                                  foreach ($searchArray as $k => $v)
+                                  {
+                                    if ($k === $currentPath[0])
+                                    {
+                                      array_shift($currentPath);
+
+                                      if (is_array($v) && count($currentPath) !== 0)
+                                      {
+                                        $replace(&$searchArray[$k], $currentPath, $value);
+                                      }
+                                      elseif (count($currentPath) === 0)
+                                      {
+                                        $searchArray[$k] = $value;
+                                      }
+                                    }
+                                  }
+                                };
+
+                        $replace($mainEnv, $currentPath, $valueToReplace);
+                      }
+                      elseif (is_array($item)) // if current item is an array
+                      {
+                        $currentPath[] = $key; // add item's key to current path
+
+                        array_walk($item, $map); // and dig into the current item
+                      }
+                      else //wrong path
+                      {
+                        $currentPath = array(); //reset
+                      }
+                    };
+
+            //run trough the main conf environnement
+            array_walk($mainEnv, $map);
+
+            //once done
+            //reduce the paths to process
+            unset($pathToprocess[$kpath]);
+
+            break;
+          }
+        }
+      }
+    }
+    
+    if(count($allEnvs) >= 1)
+    {
+      foreach($allEnvs as $extendedEnv)
+       $mainEnv = array_replace_recursive($mainEnv, $extendedEnv);
+    }
+
+    return $mainEnv;
+  }
+
+}
diff --git a/lib/Alchemy/Phrasea/Core/Configuration/Parser/ParserInterface.php b/lib/Alchemy/Phrasea/Core/Configuration/Parser/ParserInterface.php
new file mode 100644
index 0000000000..60d61cf808
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Core/Configuration/Parser/ParserInterface.php
@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2010 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Alchemy\Phrasea\Core\Configuration\Parser;
+
+/**
+ *
+ * @package
+ * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
+ * @link        www.phraseanet.com
+ */
+
+interface ParserInterface
+{
+  /**
+   * Parse the configuration file $file  to an array
+   * 
+   * @param \SplFileObject $file the file to parse
+   * @return Array
+   */
+  public function parse(\SplFileObject $file);
+}
\ No newline at end of file
diff --git a/lib/Alchemy/Phrasea/Core/Configuration/Parser/Yaml.php b/lib/Alchemy/Phrasea/Core/Configuration/Parser/Yaml.php
new file mode 100644
index 0000000000..a989cd06d0
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Core/Configuration/Parser/Yaml.php
@@ -0,0 +1,39 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2010 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+namespace Alchemy\Phrasea\Core\Configuration\Parser;
+
+use Symfony\Component\Yaml\Yaml as SfYaml;
+/**
+ *
+ * @package
+ * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
+ * @link        www.phraseanet.com
+ */
+
+class Yaml implements ParserInterface
+{
+  /**
+   *
+   * @Override
+   */
+  public function parse(\SplFileObject $file)
+  {
+    try
+    {
+      return SfYaml::parse($file->getPathname());
+    }
+    catch(\Exception $e)
+    {
+      throw new \Exception(sprintf('Failed to parse the configuration file %s', $e->getMessage()));
+    }
+  }
+
+}
\ No newline at end of file
diff --git a/lib/Alchemy/Phrasea/Core/Configuration/PhraseaConfiguration.php b/lib/Alchemy/Phrasea/Core/Configuration/PhraseaConfiguration.php
new file mode 100644
index 0000000000..b88df26ff2
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Core/Configuration/PhraseaConfiguration.php
@@ -0,0 +1,81 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2010 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Alchemy\Phrasea\Core\Configuration;
+
+/**
+ *
+ * @package
+ * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
+ * @link        www.phraseanet.com
+ */
+class PhraseaConfiguration implements ConfigurationSpecification
+{
+
+  /**
+   *
+   * @Override
+   */
+  public function getNonExtendablePath()
+  {
+    return array('doctrine', 'dbal');
+  }
+
+  /**
+   *
+   * @Override
+   */
+  public function getConfFileFromEnvName($name)
+  {
+    return new \SplFileObject(sprintf("/%s/config_%s.%s"
+                            , $this->getConfigurationFilePath()
+                            , $name
+                            , $this->getConfFileExtension())
+    );
+  }
+
+  /**
+   *
+   * @Override
+   */
+  public function getConfigurationFilePath()
+  {
+    return __DIR__ . '/../../../../../config';
+  }
+
+  /**
+   *
+   * @Override
+   */
+  public function getConfFileExtension()
+  {
+    return 'yml';
+  }
+
+  /**
+   *
+   * @Override
+   */
+  public function isExtended(Array $env)
+  {
+    return isset($env[self::EXTENDED_KEYWORD]);
+  }
+
+  /**
+   *
+   * @Override
+   */
+  public function getExtendedEnvName(Array $env)
+  {
+    return $this->isExtended($env) ? $env[self::EXTENDED_KEYWORD] : null;
+  }
+
+}