diff --git a/composer.json b/composer.json
index 11049bd..3f17caa 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,10 @@
         "smarty-gettext/smarty-gettext": "^1.6",
         "smarty-gettext/tsmarty2c": "^0.2.1",
         "sepia/po-parser": "^6.0",
-        "sentry/sdk": "^3.3"
+        "sentry/sdk": "^3.3",
+        "ext-pdo": "^7.3",
+        "ext-json": "^7.3",
+        "ext-yaml": "^2.0"
     },
     "require-dev": {
         "phpstan/phpstan": "^1.9"
diff --git a/composer.lock b/composer.lock
index 3c13090..434f63f 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "372e3ce1ce40fd466379b8709b0f7c5a",
+    "content-hash": "bbb5f6bafa8928dce90eb5d63dbc0376",
     "packages": [
         {
             "name": "brenard/php-unidecode",
@@ -2856,7 +2856,11 @@
     },
     "prefer-stable": false,
     "prefer-lowest": false,
-    "platform": [],
+    "platform": {
+        "ext-pdo": "^7.4",
+        "ext-yaml": "^2.1",
+        "ext-json": "^7.4"
+    },
     "platform-dev": [],
-    "plugin-api-version": "2.3.0"
+    "plugin-api-version": "2.0.0"
 }
diff --git a/includes/.gitignore b/includes/.gitignore
index 529bf01..8cf7685 100644
--- a/includes/.gitignore
+++ b/includes/.gitignore
@@ -1 +1 @@
-config.local.php
+config.local.yml
diff --git a/includes/config.inc.php b/includes/config.inc.php
deleted file mode 100644
index 3339ce1..0000000
--- a/includes/config.inc.php
+++ /dev/null
@@ -1,155 +0,0 @@
-<?php
-
-// Public root URL
-$public_root_url = "http://127.0.0.1/eesyphp";
-
-// Application root data directory
-$data_dir = $root_dir_path."/data";
-
-// Temporary files root directory
-$tmp_root_dir = "$data_dir/tmp";
-
-// Temporary uploading files directory
-$upload_tmp_dir = "$tmp_root_dir/uploading";
-
-// Main pagetitle
-$main_pagetitle = "Eesyphp";
-
-// Theme CSS file
-$included_css_files = array();
-
-// Log configuration
-
-// Logs directory path
-$logs_dir_path = "$data_dir/logs";
-
-// Log file path
-if (php_sapi_name() == "cli")
-  $log_file = "$logs_dir_path/cli.log";
-else
-  $log_file = "$logs_dir_path/app.log";
-
-// Log level (TRACE / DEBUG / INFO / WARNING / ERROR / FATAL)
-$log_level = 'INFO';
-
-// Debug Ajax request/response
-$debug_ajax = false;
-
-// Log PHP errors levels (as specified to set_error_handler())
-// Default:
-// - In TRACE or DEBUG: E_ALL & ~E_STRICT
-// - Otherwise: E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED
-// $log_php_errors_levels = E_ALL & ~E_STRICT;
-
-/*
- * Sentry configuration
- */
-
-// Sentry DSN
-$sentry_dsn = null;
-
-// Log PHP errors in Sentry: list of errors types to logs
-// Note: must also match with $log_php_errors_levels.
-// See: https://www.php.net/manual/fr/errorfunc.constants.php
-$sentry_php_error_types = array(
-  E_ERROR, E_PARSE, E_CORE_ERROR, E_COMPILE_ERROR, E_USER_ERROR,
-  E_RECOVERABLE_ERROR,E_DEPRECATED,
-);
-
-// Traces sample rate (between 0 and 1)
-// Note: this parameter permit to determine how many transactions (=~ access) are traced and
-// sent to Sentry, for instance, 0.2 meen that 20% of the transactions will be traced. In dev
-// mode, set to 1 if you want all transactions are sent to Sentry.
-// Default: 0.2
-$sentry_traces_sample_rate = 0.2;
-
-/*
- * Smarty template configuration
- */
-
-// Smarty directories
-$smarty_templates_dir = "$root_dir_path/templates";
-$smarty_templates_c_dir = "$tmp_root_dir/templates_c";
-
-// Default locale (see locales directory for available languages list)
-$default_locale = 'en_US.UTF8';
-
-// Session
-$session_timeout = 1800;        // Session timeout dur to inactivity (in seconds)
-$session_max_duration = 43200;  // Session max duration (in seconds, default : 12h)
-
-/**
- * Database configuration
- **/
-
-// Sqlite
-$db_dsn="sqlite:$root_dir_path/data/db.sqlite3";
-$db_user=null;
-$db_pwd=null;
-$db_options=array();
-
-// Date/Datetime format in database (strptime format)
-$db_date_format = '%s';
-$db_datetime_format = '%s';
-
-/*
-// Postgresql
-$db_dsn="pgsql:host=localhost;port=5432;dbname=items";
-$db_user="items";
-$db_pwd="items";
-$db_options=array();
-
-// Date/Datetime format in database (strptime format)
-$db_date_format = '%Y-%m-%d';                // Exemple : 2018-10-12
-$db_datetime_format = '%Y-%m-%d %H:%M:%S';   // Exemple : 2018-10-12 18:06:59
-*/
-
-/*
-// MariaDB / MySQL
-$db_dsn="mysql:host=localhost;dbname=items";
-$db_user="items";
-$db_pwd="items";
-$db_options=array();
-
-// Date/Datetime format in database (strptime format)
-$db_date_format = '%Y-%m-%d';               // Exemple : 2018-10-12
-$db_datetime_format = '%Y-%m-%d %H:%M:%S';  // Exemple : 2018-10-12 18:06:59
-*/
-
-/*
- * Config Mail
- */
-
-// PHP PEAR Mail and Mail_Mine paths
-$php_mail_path = 'Mail.php';
-$php_mail_mime_path = 'Mail/mime.php';
-
-/*
- * Sending method :
- *  - mail : use PHP mail function
- *  - sendmail : use sendmail system command
- *  - smtp : use an SMTP server (PHP PEAR Net_SMTP required)
- */
-$mail_send_method = 'smtp';
-
-/*
- * Sending parameters
- * See : http://pear.php.net/manual/en/package.mail.mail.factory.php
- */
-$mail_send_params = NULL;
-
-// Headers add to all e-mails sent
-$mail_headers = array();
-
-// Email sender address (for all emails sent by the application)
-$mail_sender = "noreply@example.org";
-
-// Catch all e-mails sent to a configured e-mail address
-$mail_catch_all = false;
-
-/**
- * Web Stats JS code
- */
-$webstats_js_code = '';
-
-# vim: tabstop=2 shiftwidth=2 softtabstop=2 expandtab
diff --git a/includes/config.yml b/includes/config.yml
new file mode 100644
index 0000000..d6e3de6
--- /dev/null
+++ b/includes/config.yml
@@ -0,0 +1,170 @@
+# Public root URL
+public_root_url: "http://127.0.0.1/eesyphp"
+
+# Application root data directory
+data_directory: "${root_directory_path}/data"
+
+# Temporary files root directory
+tmp_root_directory: "${data_directory}/tmp"
+
+# Temporary uploading files directory
+upload_tmp_directory: ${tmp_root_directory}/uploading"
+
+# Main pagetitle
+main_pagetitle: "Eesyphp"
+
+# Theme CSS file
+included_css_files:
+  #- css/custom.css
+included_js_files:
+  #- js/custom.js
+
+# Debug Ajax request/response
+debug_ajax: false
+
+#
+# Log configuration
+#
+log:
+  # Logs directory path
+  directory_path: "${data_directory}/logs"
+
+  # CLI log file path
+  cli_file_path: "${log.directory_path}/cli.log"
+
+  # Log file path
+  file_path: "${log.directory_path}/app.log"
+
+  # Log level (TRACE / DEBUG / INFO / WARNING / ERROR / FATAL)
+  level: 'INFO'
+
+  # Log PHP errors levels (as specified to set_error_handler())
+  # Note: expected a list of PHP error level constants that will be resolved and combine
+  # with a bitwise operator. After the first value, the bitwise operator "|" (OR) or "^" (XOR)
+  # could be specified as contanst name prefix, otherwise the "&" (AND) operator will be used.
+  # The constant name could also be prefix with "~" or "!" (NOT) bitwise operator.
+  #
+  # Default:
+  # - In TRACE or DEBUG: E_ALL & ~E_STRICT
+  # - Otherwise: E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED
+  #log_php_errors_levels:
+  #  - E_ALL
+  #  - ~E_NOTICE
+  #  - ~E_STRICT
+  #  - ~E_DEPRECATED
+
+
+#
+# Sentry configuration
+#
+sentry:
+  # Sentry DSN
+  #dsn: null
+
+  # Log PHP errors in Sentry: list of errors types to logs
+  # See: https://www.php.net/manual/fr/errorfunc.constants.php
+  php_error_types:
+    - "E_ERROR"
+    - "E_PARSE"
+    - "E_CORE_ERROR"
+    - "E_COMPILE_ERROR"
+    - "E_USER_ERROR"
+    - "E_RECOVERABLE_ERROR"
+    - "E_DEPRECATED"
+
+
+  # Traces sample rate (between 0 and 1)
+  # Note: this parameter permit to determine how many transactions (=~ access) are traced and
+  # sent to Sentry, for instance, 0.2 meen that 20% of the transactions will be traced. In dev
+  # mode, set to 1 if you want all transactions are sent to Sentry.
+  # Default: 0.2
+  traces_sample_rate: 0.2
+
+#
+# Smarty template configuration
+#
+template:
+  # Smarty directories
+  directory: "${root_directory_path}/templates"
+  cache_directory: "${tmp_root_directory}/templates_c"
+
+#
+# Translations
+#
+i18n:
+  # Default locale (see locales directory for available languages list)
+  default_locale: 'en_US.UTF8'
+
+#
+# Session
+#
+session:
+  timeout: 1800        # Session timeout dur to inactivity (in seconds)
+  max_duration: 43200  # Session max duration (in seconds, default : 12h)
+
+#
+# Database configuration
+#
+db:
+  # Sqlite
+  dsn: "sqlite:${data_directory}/db.sqlite3"
+  options: null
+
+  # Date/Datetime format in database (strptime format)
+  date_format: '%s'
+  datetime_format: '%s'
+
+  # Postgresql
+  #dsn: "pgsql:host=localhost;port=5432;dbname=items"
+  #user: "items"
+  #pwd: "items"
+  #options: null
+
+  # Date/Datetime format in database (strptime format)
+  #date_format: '%Y-%m-%d'                # Exemple : 2018-10-12
+  #datetime_format: '%Y-%m-%d %H:%M:%S'   # Exemple : 2018-10-12 18:06:59
+
+  # MariaDB / MySQL
+  #dsn: "mysql:host=localhost;dbname=items"
+  #user: "items"
+  #pwd: "items"
+  #options: null
+
+  # Date/Datetime format in database (strptime format)
+  #date_format: '%Y-%m-%d'               # Exemple : 2018-10-12
+  #datetime_format: '%Y-%m-%d %H:%M:%S'  # Exemple : 2018-10-12 18:06:59
+
+
+#
+# Email configuration
+#
+email:
+  # PHP PEAR Mail and Mail_Mine paths
+  php_mail_path: 'Mail.php'
+  php_mail_mime_path: 'Mail/mime.php'
+
+
+  # Sending method :
+  #  - mail : use PHP mail function
+  #  - sendmail : use sendmail system command
+  #  - smtp : use an SMTP server (PHP PEAR Net_SMTP required)
+  send_method: 'smtp'
+
+  # Sending parameters
+  # See : http:#pear.php.net/manual/en/package.mail.mail.factory.php
+  send_params: NULL
+
+  # Headers add to all e-mails sent
+  headers:
+    #- "CC: support@example.com"
+
+  # Email sender address (for all emails sent by the application)
+  sender: "noreply@example.org"
+
+  # Catch all e-mails sent to a configured e-mail address
+  catch_all: false
+
+# Web Stats JS code
+webstats_js_code: ''
+
+# vim: tabstop=2 shiftwidth=2 softtabstop=2 expandtab
diff --git a/includes/core.php b/includes/core.php
index a938432..13e00e9 100644
--- a/includes/core.php
+++ b/includes/core.php
@@ -1,13 +1,9 @@
 <?php
 
-use EesyPHP\Email;
+use EesyPHP\App;
+use EesyPHP\Config;
 use EesyPHP\I18n;
-use EesyPHP\Log;
-use EesyPHP\SentryIntegration;
 use EesyPHP\SentrySpan;
-use EesyPHP\SentryTransaction;
-use EesyPHP\Session;
-use EesyPHP\Url;
 
 error_reporting(E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED);
 
@@ -31,39 +27,20 @@ set_include_path($root_dir_path.'/includes' . PATH_SEPARATOR . get_include_path(
 // Load composer autoload.php
 require("$root_dir_path/vendor/autoload.php");
 
-// Load configuration
-require_once('config.inc.php');
-
-// Load local configuration file is present
-if (is_file("$root_dir_path/includes/config.local.php")) {
-  require "$root_dir_path/includes/config.local.php";
-}
-
-SentryIntegration :: init(
-  isset($sentry_dsn)?$sentry_dsn:null,
-  isset($sentry_traces_sample_rate)?$sentry_traces_sample_rate:null,
-  isset($sentry_php_error_types)?$sentry_php_error_types:null,
+// Initialize EesyPHP application
+App::init(
+  "$root_dir_path/includes/config.yml",
+  array(
+    'overwrite_config_files' => array(
+      "$root_dir_path/includes/config.local.yml",
+    ),
+  ),
+  $root_dir_path
 );
-$sentry_transaction = new SentryTransaction();
 
 $sentry_span = new SentrySpan('core.init', 'Core initialization');
 
-// Define upload_tmp_dir
-if (isset($upload_tmp_dir))
-  ini_set('upload_tmp_dir', $upload_tmp_dir);
-
-if (!isset($log_file))
-  die('Log file path not configured');
-Log::init(
-  $log_file,
-  isset($log_level)?$log_level:null,
-  isset($log_php_errors_levels)?$log_php_errors_levels:null
-);
 require_once('functions.php');
-Session :: init(
-  isset($session_max_duration)?$session_max_duration:null,
-  isset($session_timeout)?$session_timeout:null
-);
 
 // Nomenclatures
 $status_list = array (
@@ -72,29 +49,14 @@ $status_list = array (
   'refused' => I18n :: ___('Refused'),
   'archived' => I18n :: ___('Archived'),
 );
+foreach($status_list as $key => $value)
+  $status_list[$key] = _($value);
 
 require_once('cli.php');
 require_once('templates.php');
-Url::init(isset($public_root_url)?$public_root_url:null);
 require_once('url-helpers.php');
 require_once('db.php');
-Email :: init(
-  isset($mail_sender)?$mail_sender:null,
-  isset($mail_send_method)?$mail_send_method:null,
-  isset($mail_send_params)?$mail_send_params:null,
-  isset($mail_catch_all)?$mail_catch_all:null,
-  isset($mail_headers)?$mail_headers:null,
-  isset($php_mail_path)?$php_mail_path:null,
-  isset($php_mail_mime_path)?$php_mail_mime_path:null,
-);
 
-// Initialize translation
-I18n::init(
-  "$root_dir_path/locales",
-  isset($default_locale)?$default_locale:null);
-
-foreach($status_list as $key => $value)
-  $status_list[$key] = _($value);
 $sentry_span->finish();
 
 # vim: tabstop=2 shiftwidth=2 softtabstop=2 expandtab
diff --git a/includes/db.php b/includes/db.php
index 9f9a3c0..f5d67cc 100644
--- a/includes/db.php
+++ b/includes/db.php
@@ -1,5 +1,6 @@
 <?php
 
+use EesyPHP\Config;
 use EesyPHP\Db;
 use EesyPHP\Hook;
 use EesyPHP\Log;
@@ -7,12 +8,12 @@ use EesyPHP\Log;
 use Unidecode\Unidecode;
 
 $db = new Db(
-  isset($db_dsn)?$db_dsn:null,
-  isset($db_user)?$db_user:null,
-  isset($db_pwd)?$db_pwd:null,
-  isset($db_options)?$db_options:null,
-  isset($db_date_format)?$db_date_format:null,
-  isset($db_datetime_format)?$db_datetime_format:null
+  Config::get('db.dsn', null, 'string'),
+  Config::get('db.user', null, 'string'),
+  Config::get('db.password', null, 'string'),
+  Config::get('db.options', array(), 'array'),
+  Config::get('db.date_format', null, 'string'),
+  Config::get('db.datetime_format', null, 'string'),
 );
 
 /*
@@ -150,10 +151,10 @@ function delete_item($id) {
 }
 
 function search_items($params) {
-  global $db, $db_dsn;
+  global $db;
 
   // Detect PgSQL backend
-  $is_pgsql = (strpos($db_dsn, "pgsql:") === 0);
+  $is_pgsql = (strpos(Config::get('db.dsn', '', 'string'), "pgsql:") === 0);
 
   $where = array();
   if (isset($params['status']) && $params['status'] && $params['status'] != 'all')
diff --git a/includes/templates.php b/includes/templates.php
index 7e53c46..00eff22 100644
--- a/includes/templates.php
+++ b/includes/templates.php
@@ -1,5 +1,6 @@
 <?php
 
+use EesyPHP\Config;
 use EesyPHP\Date;
 use EesyPHP\Hook;
 use EesyPHP\Log;
@@ -7,12 +8,6 @@ use EesyPHP\Tpl;
 
 use function EesyPHP\format_size;
 
-Tpl :: init(
-  isset($smarty_templates_dir)?$smarty_templates_dir:null,
-  isset($smarty_templates_c_dir)?$smarty_templates_c_dir:null,
-  isset($debug_ajax)?$debug_ajax:false
-);
-
 if (php_sapi_name() == "cli")
   return true;
 
@@ -28,18 +23,16 @@ Tpl :: enable_security_mode(
 );
 
 // Defined some global template variables
-Tpl :: assign('public_root_url', isset($public_root_url)?$public_root_url:'/');
-Tpl :: assign('main_pagetitle', isset($main_pagetitle)?$main_pagetitle:null);
+Tpl :: assign('public_root_url', Config::get('public_root_url', '/', 'string'));
+Tpl :: assign('main_pagetitle', Config::get('main_pagetitle', null, 'string'));
 Tpl :: assign('session_key', $_SESSION['session_key']);
 
 // Handle CSS & JS files included
-if (isset($included_css_files) && is_array($included_css_files))
-  Tpl :: add_css_file($included_css_files);
-if (isset($included_js_files) && is_array($included_js_files))
-  Tpl :: add_css_file($included_js_files);
+Tpl :: add_css_file(Config::get('included_css_files', array(), 'array'));
+Tpl :: add_js_file(Config::get('included_js_files', array(), 'array'));
 
 function define_common_template_variables($event) {
-  global $status_list, $admin, $webstats_js_code;
+  global $status_list, $admin;
   Tpl :: assign(
     'status_list',
     isset($status_list) && is_array($status_list)?
@@ -48,7 +41,7 @@ function define_common_template_variables($event) {
   Tpl :: assign('admin', isset($admin) && $admin);
   Tpl :: assign(
     'webstats_js_code',
-    isset($webstats_js_code)?$webstats_js_code:null);
+    Config::get('webstats_js_code', null, 'string'));
 }
 Hook :: register('before_displaying_template', 'define_common_template_variables');
 
diff --git a/phpstan.neon b/phpstan.neon
index 58a3784..9e22264 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -20,10 +20,6 @@ parameters:
         -
             message: "#Call to static method isError\\(\\) on an unknown class PEAR\\.#"
             path: src/Email.php
-        -
-            message: "#Variable \\$root_dir_path might not be defined\\.#"
-            paths:
-                - includes/config.inc.php
         -
             message: "#Variable \\$status_list might not be defined\\.#"
             paths:
diff --git a/src/App.php b/src/App.php
new file mode 100644
index 0000000..0ea6ba4
--- /dev/null
+++ b/src/App.php
@@ -0,0 +1,103 @@
+<?php
+
+namespace EesyPHP;
+
+class App {
+
+  /**
+   * Options
+   * @var array
+   */
+  protected static $options = array();
+
+  /**
+   * Root directory path
+   * @var string|null
+   */
+  protected static $root_directory_path = null;
+
+  /**
+   * Initialization
+   * @param string|null $config_file Application configuration file path
+   * @param array|null $options Application options (default: null)
+   * @param string|null $root_directory_path Application root directory path (default: null)
+   * @return void
+   */
+  public static function init($config_file, $options=null, $root_directory_path=null) {
+    if (is_array($options)) self :: $options = $options;
+
+    if (is_null($root_directory_path)) {
+      $traces = debug_backtrace();
+      $root_directory_path = realpath(dirname($traces[0]['file']).'/../');
+    }
+    self :: $root_directory_path = $root_directory_path;
+    Config::register_extra_variable('root_directory_path', $root_directory_path);
+
+    $config_file = Config::replace_variables($config_file);
+    if (!Config::load($config_file)) {
+      Log::fatal('Fail to load configuration file (%s)', $config_file);
+      exit(1);
+    }
+
+    // Load overwrite configuration file
+    foreach (self :: get_option('overwrite_config_files', array(), 'array') as $file) {
+      $file = Config::replace_variables($file);
+      if (is_file($file)) Config::load($file, true);
+    }
+
+    if (self :: get_option('sentry.enabled', true, 'bool'))
+      SentryIntegration :: init();
+    $sentry_transaction = new SentryTransaction();
+    $sentry_span = new SentrySpan('app.init', 'Application initialization');
+
+    // Define upload_tmp_dir
+    if (is_string(Config::get('upload_tmp_directory')))
+      ini_set('upload_tmp_dir', Config::get('upload_tmp_directory'));
+
+    if (self :: get_option('log.enabled', true, 'bool'))
+      Log::init();
+    if (self :: get_option('session.enabled', true, 'bool'))
+      Session::init();
+    if (self :: get_option('template.enabled', true, 'bool'))
+      Tpl :: init();
+    if (self :: get_option('url.enabled', true, 'bool'))
+      Url::init();
+    if (self :: get_option('mail.enabled', true, 'bool'))
+      Email :: init();
+    if (self :: get_option('i18n.enabled', true, 'bool'))
+      I18n::init();
+    $sentry_span->finish();
+  }
+
+  /**
+   * Get a specific option value
+   *
+   * @param string $key The configuration variable key
+   * @param mixed $default The default value to return if configuration variable
+   *                       is not set (Default : null)
+   * @param string $cast   The type of expected value. The configuration variable
+   *                       value will be cast as this type. Could be : bool, int,
+   *                       float or string. (Optional, default : raw value)
+   * @param bool $split If true, $cast is 'array' and value retreived from configuration
+   *                    is a string, split the value by comma (optional, default: true)
+   * @return mixed The configuration variable value
+   **/
+  public static function get_option($key, $default=null, $cast=null, $split=true) {
+    return Config::get(
+      $key,
+      Config::loaded()?Config::get($key, $default, $cast, $split):$default,
+      $cast,
+      $split,
+      self :: $options
+    );
+  }
+
+  /**
+   * Retreive application root directory path
+   * @return string|null
+   */
+  public static function root_directory_path() {
+    return self :: $root_directory_path?self :: $root_directory_path:'.';
+  }
+
+}
diff --git a/src/Config.php b/src/Config.php
new file mode 100644
index 0000000..4e7efbc
--- /dev/null
+++ b/src/Config.php
@@ -0,0 +1,209 @@
+<?php
+
+Namespace EesyPHP;
+
+
+Class Config {
+
+  /**
+   * Configuration file path
+   * @var string|null
+   */
+  private static $filepath = null;
+
+  /**
+   * Loaded configuration data
+   * @var array|null
+   */
+  private static $config = null;
+
+  /**
+   * Extra registered variables usable in configuration file
+   * @var array
+   */
+  private static $extra_variables = array();
+
+  /**
+   * Load configuration file
+   * @param string $filepath The configuration file path
+   * @param bool $extra Load as an extra configuration file (default: false)
+   * @return bool
+   */
+  public static function load($filepath, $extra=false) {
+    if (!file_exists($filepath)) {
+      Log :: error("Configuration file not found ($filepath)");
+      return false;
+    }
+    $config = yaml_parse_file($filepath);
+    if (!is_array($config) || empty($config)) {
+      Log :: error("Fail to load %sconfiguration file (%s)", $extra?'extra ':'', $filepath);
+      return false;
+    }
+    if (!$extra || !is_array(self :: $config))
+      self :: $config = $config;
+    else
+      self :: $config = array_replace_recursive(self :: $config, $config);
+    if (!$extra)
+      self :: $filepath = $filepath;
+    return true;
+  }
+
+  /**
+   * Check if configuration is loaded
+   * @return bool
+   */
+  public static function loaded() {
+    return is_array(self :: $config);
+  }
+
+  /**
+   * Save configuration
+   * @param string|null $filepath The configuration file path
+   * @param bool $overwrite Overwrite existing file (optional, default: true)
+   * @return bool
+   */
+  public static function save($filepath=null, $overwrite=true) {
+    if (!self :: loaded()) {
+      Log :: error("Configuration not loaded, can't save it.");
+      return false;
+    }
+    if (!$filepath) $filepath = self :: $filepath;
+    if (!$filepath) {
+      Log :: error("No configuration file set or pass as parameter");
+      return false;
+    }
+    if (file_exists($filepath)) {
+      if (!$overwrite) {
+        Log :: error("Configuration file already exist (%s)", $filepath);
+        return false;
+      }
+      if (!is_writable($filepath)) {
+        Log :: error(
+          "Configuration file already exist and is not writable (%s)",
+          $filepath);
+        return false;
+      }
+    }
+    if (!yaml_emit_file($filepath, self :: $config)) {
+      Log :: error("Fail to save configuration in '%s'", $filepath);
+      return false;
+    }
+    Log :: info("Configuration saved in '%s'", $filepath);
+    return true;
+  }
+
+  /**
+   * Register extra variable usable in configuration file
+   * @param string $key The variable key
+   * @param mixed $value The variable value
+   */
+  public static function register_extra_variable($key, $value) {
+    self :: $extra_variables[$key] = $value;
+  }
+
+  /**
+   * Get a specific configuration variable value
+   *
+   * @param string $key The configuration variable key
+   * @param mixed $default The default value to return if configuration variable
+   *                       is not set (Default : null)
+   * @param string $cast   The type of expected value. The configuration variable
+   *                       value will be cast as this type. Could be : bool, int,
+   *                       float or string. (Optional, default : raw value)
+   * @param bool $split If true, $cast=='array' and $value is a string, split
+   *                    the value by comma (optional, default: false)
+   * @param array|null $config Optional configuration to use instead of current loaded configuration
+   * @return mixed The configuration variable value
+   **/
+  public static function get($key, $default=null, $cast=null, $split=false, &$config=null) {
+    if (array_key_exists($key, self :: $extra_variables)) {
+      $value = self :: $extra_variables[$key];
+    }
+    else if (!is_array($config) && !self :: loaded()) {
+      Log :: fatal('Configuration not loaded (on getting %s)', $key);
+      exit(1);
+    }
+    else {
+      $exploded_key = explode('.', $key);
+      if (!is_array($exploded_key)) return self :: replace_variables($default);
+      $value = is_array($config)?$config:self :: $config;
+      foreach ($exploded_key as $k) {
+        if (!is_array($value) || !isset($value[$k]))
+          return self :: replace_variables($default);
+        $value = $value[$k];
+      }
+    }
+    return self :: replace_variables(cast($value, $cast, $split));
+  }
+
+  /**
+   * Replace variable in specified value
+   * @param mixed $value
+   * @return mixed
+   */
+  public static function replace_variables($value) {
+    if (is_array($value)) {
+      foreach(array_keys($value) as $key) {
+        if (is_string($value[$key]) || is_array($value[$key]))
+          $value[$key] = self :: replace_variables($value[$key]);
+      }
+    }
+    else if (is_string($value)) {
+      $iteration = 0;
+      while (preg_match('/\$\{([^\}]+)\}/', $value, $m)) {
+        if ($iteration > 20) {
+          Log::fatal('Config::replace_variables(%s): max iteration reached');
+          return $value;
+        }
+        $value = str_replace($m[0], self :: get($m[1], '', 'string'), $value);
+        $iteration++;
+      }
+    }
+    return $value;
+  }
+
+  /**
+   * Get list of keys of a specific configuration variable
+   *
+   * @param string $key The configuration variable key
+   *
+   * @return array An array of the keys of a specific configuration variable
+   **/
+  public static function keys($key) {
+    $value = self :: get($key);
+    return (is_array($value)?array_keys($value):array());
+  }
+
+  /**
+   * Set a configuration variable
+   *
+   * @param string $key The configuration variable key
+   * @param mixed $value The configuration variable value
+   * @param array|null &$config Optional configuration to use instead of current loaded configuration
+   *
+   * @return boolean
+   **/
+  public static function set($key, $value, &$config=null) {
+    $exploded_key = explode('.', $key);
+    if (!is_array($exploded_key)) return false;
+    if (is_array($config)) {
+      $parent = &$config;
+    }
+    else {
+      if (!is_array(self :: $config))
+        self :: $config = array();
+      $parent = &self :: $config;
+    }
+    for ($i=0; $i < count($exploded_key) - 1; $i++) {
+      $k = $exploded_key[$i];
+      if (!array_key_exists($k, $config))
+        $config[$k] = array();
+      $config = &$config[$k];
+    }
+    $config[array_pop($exploded_key)] = $value;
+    return true;
+  }
+
+}
+
+# vim: tabstop=4 shiftwidth=4 softtabstop=4 expandtab
diff --git a/src/Email.php b/src/Email.php
index d5c2bec..ff86e5a 100644
--- a/src/Email.php
+++ b/src/Email.php
@@ -59,18 +59,40 @@ class Email {
 
   /**
    * Initialization
-   * @param string|null $php_mail_path PHP PEAR Mail lib path (optional, default: Mail.php)
-   * @param string|null $php_mail_mime_path PHP PEAR Mail lib path (optional, default: Mail/mime.php)
+   * @param string|null $php_mail_path PHP PEAR Mail lib path (optional, default: from
+   *                    email.php_mail_path config key if set, 'Mail.php' otherwise)
+   * @param string|null $php_mail_mime_path PHP PEAR Mail lib path (optional, default: from
+   *                    email.php_mail_mime_path config key if set, 'Mail/mime.php' otherwise)
    * @return void
    */
   public static function init($sender=null, $send_method=null, $send_params=null, $catch_all=null,
                               $headers=null, $php_mail_path=null, $php_mail_mime_path=null) {
+    if (is_null($sender))
+      $sender = Config::get('email.sender', null, 'string');
     if ($sender) self :: $sender = $sender;
+
+    if (is_null($send_method))
+      $send_method = Config::get('email.send_method', null, 'string');
     if ($send_method) self :: $send_method = $send_method;
+
+    if (is_null($send_params))
+      $send_params = Config::get('email.send_params', null, 'array');
     if ($send_params) self :: $send_params = $send_params;
+
+    if (is_null($catch_all))
+      $catch_all = Config::get('email.catch_all');
     if ($catch_all) self :: $catch_all = $catch_all;
+
+    if (is_null($headers))
+      $headers = Config::get('email.headers', null, 'array');
     if ($headers) self :: $headers = $headers;
+
+    if (is_null($php_mail_path))
+      $php_mail_path = Config::get('email.php_mail_path', null, 'string');
     if ($php_mail_path) self :: $php_mail_path = $php_mail_path;
+
+    if (is_null($php_mail_mime_path))
+      $php_mail_mime_path = Config::get('email.php_mail_mime_path', null, 'string');
     if ($php_mail_mime_path) self :: $php_mail_mime_path = $php_mail_mime_path;
   }
 
diff --git a/src/I18n.php b/src/I18n.php
index 66b8dfe..83b06d9 100644
--- a/src/I18n.php
+++ b/src/I18n.php
@@ -27,15 +27,22 @@ class I18n {
    * system.
    *
    * @param string|null $root_path The root directory path of translation files
-   *                               (optional, default: ./locales)
+   *                    (optional, default: from i18n.root_directory config key if set,
+   *                    '${root_directory_path}/locales' otherwise)
    * @param string|null $default_locale The default locale
-   *                                    (optional, default: en_US.UTF8)
+   *                    (optional, default: from i18n.default_locale config key if set,
+   *                    'en_US.UTF8' otherwise)
    * @return void
    */
   public static function init($root_path=null, $default_locale=null) {
-    global $root_dir_path;
+    if (is_null($root_path))
+      self :: $root_path = Config::get(
+        'i18n.root_directory', '${root_directory_path}/locales', 'string');
     if (!is_null($root_path))
       self :: $root_path = $root_path;
+
+    if (is_null($default_locale))
+      self :: $default_locale = Config::get('i18n.default_locale', null, 'string');
     if (!is_null($default_locale))
       self :: $default_locale = $default_locale;
 
@@ -50,7 +57,11 @@ class I18n {
         $lang = $_REQUEST['lang'];
         Log :: trace("Select lang from request parameter: '$lang'");
       }
-      elseif (isset($_SESSION['lang']) && in_array($_SESSION['lang'], $available_langs) && !isset($_REQUEST['reset_lang'])) {
+      elseif (
+        isset($_SESSION['lang'])
+        && in_array($_SESSION['lang'], $available_langs)
+        && !isset($_REQUEST['reset_lang'])
+      ) {
         $lang = $_SESSION['lang'];
         Log :: trace("Restore lang from session: '$lang'");
       }
@@ -103,8 +114,7 @@ class I18n {
     $js_translation_file = "translations/$lang.js";
     if (
       php_sapi_name() != "cli"
-      && isset($root_dir_path) && $root_dir_path
-      && is_file("$root_dir_path/public_html/$js_translation_file")
+      && is_file(App :: root_directory_path()."/public_html/$js_translation_file")
       && Tpl :: initialized()
     ) {
       Tpl :: add_js_file(array("lib/babel.js", "js/translation.js", $js_translation_file));
@@ -250,14 +260,12 @@ class I18n {
    * @return void
    */
   public static function cli_extract_messages($command_args) {
-    global $root_dir_path;
-
     // Store list of generated POT files
     $pot_files = array();
 
     // List PHP files to parse
     $php_files = run_external_command(
-      array('find', escapeshellarg($root_dir_path), '-name', "'*.php'"),
+      array('find', escapeshellarg(App :: root_directory_path()), '-name', "'*.php'"),
       null,   // no STDIN data
       false   // do not escape command args (already done)
     );
@@ -284,7 +292,7 @@ class I18n {
 
     // List JS files to parse
     $js_files = run_external_command(
-      array('find', escapeshellarg("$root_dir_path/public_html/js"), '-name', "'*.js'"),
+      array('find', escapeshellarg(App :: root_directory_path()."/public_html/js"), '-name', "'*.js'"),
       null,   // no STDIN data
       false   // do not escape command args (already done)
     );
@@ -313,7 +321,7 @@ class I18n {
       // Extract messages from templates files using tsmarty2c.php
       $result = run_external_command(
         array (
-          "$root_dir_path/vendor/bin/tsmarty2c.php",
+          App :: root_directory_path()."/vendor/bin/tsmarty2c.php",
           "-o", self :: $root_path."/templates-messages.pot",
           Tpl :: templates_directory(),
         )
@@ -359,8 +367,6 @@ class I18n {
    * @return bool
    */
   public static function cli_update_messages($command_args) {
-    global $root_dir_path;
-
     $compendium_args = array();
     foreach ($command_args as $path) {
       if (!file_exists($path))
@@ -435,7 +441,7 @@ class I18n {
       return !$error;
     }
 
-    Log :: fatal(_("Fail to open root lang directory (%s)."), $root_dir_path);
+    Log :: fatal(_("Fail to open root lang directory (%s)."), App :: root_directory_path());
     return false;
   }
 
@@ -447,8 +453,6 @@ class I18n {
    * @return bool
    */
   public static function cli_compile_messages($command_args) {
-    global $root_dir_path;
-
     if ($dh = opendir(self :: $root_path)) {
       $error = False;
       while (($file = readdir($dh)) !== false) {
@@ -466,7 +470,7 @@ class I18n {
           Log :: debug(_("Lang alias symlink found: %s -> %s"), $lang, $real_lang_dir);
 
           // Create JSON catalog symlink (if not exists)
-          $js_link = "$root_dir_path/public_html/translations/$lang.js";
+          $js_link = App :: root_directory_path()."/public_html/translations/$lang.js";
           $link_target = "$real_lang_dir.js";
           if (!file_exists($js_link)) {
             if (symlink($link_target, $js_link)) {
@@ -528,7 +532,7 @@ class I18n {
 
         // Compile messages from PO file to JSON catalog file
         $json_catalog = self :: po2json($lang, $po_file);
-        $js_file = "$root_dir_path/public_html/translations/$lang.js";
+        $js_file = App :: root_directory_path()."/public_html/translations/$lang.js";
         if(!$fd = fopen($js_file, 'w')) {
           Log :: error(_("Fail to open %s JSON catalog file in write mode (%s)."),
             $lang, $js_file);
@@ -547,7 +551,7 @@ class I18n {
 
       return !$error;
     }
-    Log :: fatal(_("Fail to open root lang directory (%s)."), $root_dir_path);
+    Log :: fatal(_("Fail to open root lang directory (%s)."), App :: root_directory_path());
     return false;
   }
 
diff --git a/src/Log.php b/src/Log.php
index 249f5c0..a463dce 100644
--- a/src/Log.php
+++ b/src/Log.php
@@ -55,26 +55,69 @@ class Log {
   // Custom fatal error handler
   protected static $fatal_error_handler = null;
 
-  /*
+  /**
    * Initialization
-   * @param string $filepath
-   * @param string|null $level
-   * @param int|null $php_errors_levels
+   * @param string $filepath The log file path
+   *              (optional, default: from log.file_path or log.cli_file_path is set)
+   * @param string|null $level The log level
+   *              (optional, default: from log.level config key if set, otherwise,
+   *              see self :: $default_level)
+   * @param int|null $php_errors_levels PHP errors level as expected by set_error_handler()
+   *                 (optional, default: from log.php_errors_levels if set, E_ALL & ~E_STRICT
+   *                 if level is TRACE or DEBUG, and E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED
+   *                 otherwise)
    * @return void
    */
-  public static function init($filepath, $level=null, $php_errors_levels=null) {
-    self :: $filepath = $filepath;
+  public static function init($filepath=null, $level=null, $php_errors_levels=null) {
+    if ($filepath)
+      self :: $filepath = $filepath;
+    elseif (php_sapi_name() == 'cli')
+      self :: $filepath = Config::get(
+        'log.cli_logfile_path', Config::get('log.cli_file_path'));
+    else
+      self :: $filepath = Config::get('log.file_path');
 
     // Set log level
-    self :: set_level($level);
+    self :: set_level($level?$level:Config::get('log.level'));
 
     // Log PHP errors
-    if (!is_null($php_errors_levels))
+    if (!is_null($php_errors_levels)) {
       self :: $php_errors_levels = $php_errors_levels;
-    elseif (in_array(self :: $level, array('DEBUG', 'TRACE')))
+    }
+    elseif ($levels = Config::get('log.php_errors_levels', array(), 'array')) {
+      $code = 'self :: $php_errors_levels = ';
+      while($level = array_shift($levels)) {
+        if (!is_string($level)) continue;
+        if (!defined($level) || !is_int(constant($level))) continue;
+        $code .= $level;
+        break;
+      }
+      foreach($levels as $level) {
+        if (!is_string($level)) continue;
+        $combine_operator = '&';
+        if (in_array($level[0], array('|', '^', '&'))) {
+          $combine_operator = $level[0];
+          $level = substr($level, 1);
+        }
+        $not = false;
+        if (in_array($level[0], array('!', '~'))) {
+          $not = $level[0];
+          $level = substr($level, 1);
+        }
+        if (!defined($level) || !is_int(constant($level))) continue;
+        $code .= " $combine_operator ";
+        if ($not) $code .= "$not";
+        $code .= $level;
+      }
+      $code .= ";";
+      eval($code);
+    }
+    elseif (in_array(self :: $level, array('DEBUG', 'TRACE'))) {
       self :: $php_errors_levels = E_ALL & ~E_STRICT;
-    else
+    }
+    else  {
       self :: $php_errors_levels = E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED;
+    }
     set_error_handler(array('EesyPHP\\Log', 'on_php_error'), self :: $php_errors_levels);
 
     // Log uncatched exceptions
@@ -93,7 +136,7 @@ class Log {
 
     if (!array_key_exists($level, self :: $levels)) $level = self :: $default_level;
     if (self :: $levels[$level] < self :: $levels[self :: $level]) return true;
-    if(is_null(self :: $file_fd)) {
+    if(self :: $filepath && is_null(self :: $file_fd)) {
       self :: $file_fd = fopen(self :: $filepath, 'a');
     }
 
@@ -125,8 +168,8 @@ class Log {
       $msg[] = $message;
       $msg = implode(' - ', $msg)."\n";
     }
-
-    fwrite(self :: $file_fd, $msg);
+    if (self :: $file_fd)
+      fwrite(self :: $file_fd, $msg);
 
     if ($level == 'FATAL')
       if (!is_null(self :: $fatal_error_handler))
@@ -260,7 +303,7 @@ class Log {
       self :: $level = self :: $default_level;
       self :: warning(
         "Invalid log level value found in configuration (%s). ".
-        "Set as default (%s).", $level, self :: $default_level);
+        "Set as default (%s).", vardump($level), self :: $default_level);
     }
     else {
       self :: $level = $level;
diff --git a/src/SentryIntegration.php b/src/SentryIntegration.php
index 7f84739..8eea5eb 100644
--- a/src/SentryIntegration.php
+++ b/src/SentryIntegration.php
@@ -26,22 +26,23 @@ class SentryIntegration {
   /**
    * Initialization
    * @param string|null $dsn Sentry DSN
+   *                    (optional, default: from sentry.dsn config key if set, null otherwise)
    * @param float|null $traces_sample_rate Sentry traces sample rate
-   *                   (optional, default: 0.2)
+   *                   (optional, default: from sentry.traces_sample_rate config key if set,
+   *                   0.2 otherwise)
    * @param array<int>|null $php_error_types Types of PHP error to log in Sentry
-   *                   (optional, default: see self::$php_error_types)
+   *                        (optional, default: from sentry.php_error_types config key if set,
+   *                        otherwise, see self::$php_error_types)
    * @return void
    */
   public static function init($dsn=null, $traces_sample_rate=null,
                               $php_error_types=null) {
-    // Init Sentry (if its DSN is configured)
-    if (!$dsn) return;
-
     \Sentry\init([
-        'dsn' => $dsn,
+        'dsn' => $dsn?$dsn:Config::get('sentry.dsn'),
         'traces_sample_rate' => (
             $traces_sample_rate?
-            $traces_sample_rate:0.2
+            $traces_sample_rate:
+            Config::get('sentry.traces_sample_rate', 0.2, 'float')
         ),
     ]);
 
@@ -55,8 +56,18 @@ class SentryIntegration {
         ]);
     });
 
-    if (is_array($php_error_types))
-      self :: $php_error_types = $php_error_types;
+    if (!is_array($php_error_types))
+      $php_error_types = Config::get(
+        'sentry.php_error_types', self :: $php_error_types, 'array'
+      );
+    self :: $php_error_types = array();
+    foreach($php_error_types as $php_error_type) {
+      if (is_string($php_error_type) && defined($php_error_type))
+        $php_error_type = constant($php_error_type);
+      if (!is_int($php_error_type)) continue;
+      if (in_array($php_error_type, self :: $php_error_types)) continue;
+      self :: $php_error_types[] = $php_error_type;
+    }
     set_error_handler(
       array('EesyPHP\\SentryIntegration', 'on_php_error'),
       E_ALL
diff --git a/src/Session.php b/src/Session.php
index d8cc5c1..026e7d0 100644
--- a/src/Session.php
+++ b/src/Session.php
@@ -16,9 +16,9 @@ class Session {
   /**
    * Initialization
    * @param int|null $max_duration Session max duration in second
-   *                               (optional, default: 12h)
+   *                 (optional, default: from session.max_duration config key if set, 12h otherwise)
    * @param int|null $timeout Session inactivity timeout in second
-   *                          (optional, default: no timeout)
+   *                 (optional, default: from session.timeout config key if set, no timeout otherwise)
    * @return void
    */
   public static function init($max_duration=null, $timeout=null) {
@@ -26,6 +26,8 @@ class Session {
       return;
 
     // Define session max duration
+    if (is_null($max_duration))
+      $max_duration = Config::get('session.max_duration', null, 'int');
     if (is_int($max_duration))
       self :: $max_duration = $max_duration;
 
@@ -41,7 +43,9 @@ class Session {
     }
 
     // Handle session timeout
-    if ($timeout) {
+    if (is_null($timeout))
+      $timeout = Config::get('session.timeout', null, 'int');
+    if (is_int($timeout) && $timeout) {
       if (!isset($_SESSION['session_last_access'])) {
         Log :: debug('Set initial session last access');
         $_SESSION['session_last_access'] = time();
diff --git a/src/Tpl.php b/src/Tpl.php
index 73b3c1b..26f97e0 100644
--- a/src/Tpl.php
+++ b/src/Tpl.php
@@ -53,13 +53,20 @@ class Tpl {
   /**
    * Initialization
    * @param string $templates_dir Smarty templates directory path
+   *               (optional, default: from template.directory config key)
    * @param string $templates_c_dir Smarty cache templates directory path
+   *               (optional, default: from template.cache_directory config key)
    * @param bool $debug_ajax Enable/disable AJAX returned data debugging in logs
-   *                         (optional, default: false)
+   *             (optional, default: from template.debug_ajax or debug_ajax config keys if set,
+   *             false otherwise)
    * @return void
    */
-  public static function init($templates_dir, $templates_c_dir, $debug_ajax=false) {
+  public static function init($templates_dir=null, $templates_c_dir=null, $debug_ajax=null) {
     // Check templates/templates_c directories
+    if (is_null($templates_dir))
+      $templates_dir = Config::get('template.directory', null, 'string');
+    if (is_null($templates_c_dir))
+      $templates_c_dir = Config::get('template.cache_directory', null, 'string');
     if (!$templates_dir || !is_dir($templates_dir)) {
       Log :: fatal(
         "Template directory not found (%s)",
@@ -75,6 +82,8 @@ class Tpl {
     self :: $smarty = new Smarty();
     self :: $smarty->setTemplateDir($templates_dir);
     self :: $smarty->setCompileDir($templates_c_dir);
+    if (is_null($debug_ajax))
+      $debug_ajax = Config::get('template.debug_ajax', Config::get('debug_ajax'));
     self :: $_debug_ajax = boolval($debug_ajax);
     Log :: register_fatal_error_handler(array('\\EesyPHP\\Tpl', 'fatal_error'));
   }
diff --git a/src/Url.php b/src/Url.php
index e806a2d..5161959 100644
--- a/src/Url.php
+++ b/src/Url.php
@@ -51,11 +51,14 @@ class Url {
   /**
    * Initialization
    * @param string|null $public_root_url The application public root URL
+   *                    (optional, default: from public_root_url config key)
    * @param bool $api_mode Enable/disable API mode
    * @return void
    */
-  public static function init($public_root_url = null, $api_mode=false) {
-    if ($public_root_url) {
+  public static function init($public_root_url=null, $api_mode=false) {
+    if (is_null($public_root_url))
+      $public_root_url = Config::get('public_root_url', null, 'string');
+    if (is_string($public_root_url) && $public_root_url) {
       // Check URL end
       if (substr(self :: $public_root_url, -1) == '/')
         $public_root_url = substr($public_root_url, 0, -1);
diff --git a/src/functions.php b/src/functions.php
index 7d186eb..68eb2e7 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -49,8 +49,13 @@ function format_callable($callable) {
   return vardump($callable);
 }
 
-function check_is_empty($val) {
-  switch(gettype($val)) {
+/**
+ * Check if given value is empty
+ * @param mixed $value
+ * @return bool
+ */
+function check_is_empty($value) {
+  switch(gettype($value)) {
     case "boolean":
     case "integer":
     case "double":
@@ -59,11 +64,57 @@ function check_is_empty($val) {
       return False;
     case "array":
     case "string":
-      if ($val == "0") return false;
-      return empty($val);
+      if ($value == "0") return false;
+      return empty($value);
     case "NULL":
       return True;
   }
+  return empty($value);
+}
+
+/**
+ * Ensure the given value is an array and return an array with this value if not
+ * @param mixed $value
+ * @return array
+ */
+function ensure_is_array($value) {
+    if (is_array($value))
+        return $value;
+    if (check_is_empty($value))
+        return array();
+    return array($value);
+}
+
+/**
+ * Get a specific configuration variable value
+ *
+ * @param mixed $value The value to cast
+ * @param string $type The type of expected value. The configuration variable
+ *                     value will be cast as this type. Could be : bool, int,
+ *                     float or string.
+ * @param bool $split If true, $type=='array' and $value is a string, split
+ *                    the value by comma (optional, default: false)
+ * @return mixed The cast value
+ **/
+function cast($value, $type, $split=false) {
+    switch($type) {
+        case 'bool':
+        case 'boolean':
+            return boolval($value);
+        case 'int':
+        case 'integer':
+            return intval($value);
+        case 'float':
+            return floatval($value);
+        case 'str':
+        case 'string':
+            return strval($value);
+        case 'array':
+            if ($split && is_string($value))
+              $value = preg_split('/ *, */', $value);
+            return ensure_is_array($value);
+    }
+    return $value;
 }
 
 /*