diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index e022e1b..03b25ab 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -46,20 +46,20 @@
  *  Load the global functions
  * ------------------------------------------------------
  */
-	require(BASEPATH.'core/Common'.EXT);
+	require(BASEPATH.'core/Common.php');
 
 /*
  * ------------------------------------------------------
  *  Load the framework constants
  * ------------------------------------------------------
  */
-	if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/constants'.EXT))
+	if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/constants.php'))
 	{
-		require(APPPATH.'config/'.ENVIRONMENT.'/constants'.EXT);
+		require(APPPATH.'config/'.ENVIRONMENT.'/constants.php');
 	}
 	else
 	{
-		require(APPPATH.'config/constants'.EXT);
+		require(APPPATH.'config/constants.php');
 	}
 
 /*
@@ -224,7 +224,7 @@
  *
  */
 	// Load the base controller class
-	require BASEPATH.'core/Controller'.EXT;
+	require BASEPATH.'core/Controller.php';
 
 	function &get_instance()
 	{
@@ -232,20 +232,20 @@
 	}
 
 
-	if (file_exists(APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller'.EXT))
+	if (file_exists(APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php'))
 	{
-		require APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller'.EXT;
+		require APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php';
 	}
 
 	// Load the local application controller
 	// Note: The Router class automatically validates the controller path using the router->_validate_request().
 	// If this include fails it means that the default controller in the Routes.php file is not resolving to something valid.
-	if ( ! file_exists(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().EXT))
+	if ( ! file_exists(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().'.php'))
 	{
 		show_error('Unable to load your default controller. Please make sure the controller specified in your Routes.php file is valid.');
 	}
 
-	include(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().EXT);
+	include(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().'.php');
 
 	// Set a mark point for benchmarking
 	$BM->mark('loading_time:_base_classes_end');
@@ -318,12 +318,12 @@
 				$method = (isset($x[1]) ? $x[1] : 'index');
 				if ( ! class_exists($class))
 				{
-					if ( ! file_exists(APPPATH.'controllers/'.$class.EXT))
+					if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
 					{
 						show_404("{$class}/{$method}");
 					}
 
-					include_once(APPPATH.'controllers/'.$class.EXT);
+					include_once(APPPATH.'controllers/'.$class.'.php');
 					unset($CI);
 					$CI = new $class();
 				}
diff --git a/system/core/Common.php b/system/core/Common.php
index 1aca809..d1e8e77 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -128,13 +128,13 @@
 		// thenin the local application/libraries folder
 		foreach (array(BASEPATH, APPPATH) as $path)
 		{
-			if (file_exists($path.$directory.'/'.$class.EXT))
+			if (file_exists($path.$directory.'/'.$class.'.php'))
 			{
 				$name = $prefix.$class;
 
 				if (class_exists($name) === FALSE)
 				{
-					require($path.$directory.'/'.$class.EXT);
+					require($path.$directory.'/'.$class.'.php');
 				}
 
 				break;
@@ -142,13 +142,13 @@
 		}
 
 		// Is the request a class extension?  If so we load it too
-		if (file_exists(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.EXT))
+		if (file_exists(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.'.php'))
 		{
 			$name = config_item('subclass_prefix').$class;
 
 			if (class_exists($name) === FALSE)
 			{
-				require(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.EXT);
+				require(APPPATH.$directory.'/'.config_item('subclass_prefix').$class.'.php');
 			}
 		}
 
@@ -157,7 +157,7 @@
 		{
 			// Note: We use exit() rather then show_error() in order to avoid a
 			// self-referencing loop with the Excptions class
-			exit('Unable to locate the specified class: '.$class.EXT);
+			exit('Unable to locate the specified class: '.$class.'.php');
 		}
 
 		// Keep track of what we just loaded
@@ -209,9 +209,9 @@
 		}
 
 		// Is the config file in the environment folder?
-		if ( ! defined('ENVIRONMENT') OR ! file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config'.EXT))
+		if ( ! defined('ENVIRONMENT') OR ! file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config.php'))
 		{
-			$file_path = APPPATH.'config/config'.EXT;
+			$file_path = APPPATH.'config/config.php';
 		}
 
 		// Fetch the config file
diff --git a/system/core/Config.php b/system/core/Config.php
index 863c5ef..4493ff2 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -80,7 +80,7 @@
 	 */
 	function load($file = '', $use_sections = FALSE, $fail_gracefully = FALSE)
 	{
-		$file = ($file == '') ? 'config' : str_replace(EXT, '', $file);
+		$file = ($file == '') ? 'config' : str_replace('.php', '', $file);
 		$found = FALSE;
 		$loaded = FALSE;
 
@@ -92,7 +92,7 @@
 
 			foreach ($check_locations as $location)
 			{
-				$file_path = $path.'config/'.$location.EXT;
+				$file_path = $path.'config/'.$location.'.php';
 
 				if (in_array($file_path, $this->is_loaded, TRUE))
 				{
@@ -152,7 +152,7 @@
 			{
 				return FALSE;
 			}
-			show_error('The configuration file '.$file.EXT.' does not exist.');
+			show_error('The configuration file '.$file.'.php'.' does not exist.');
 		}
 
 		return TRUE;
diff --git a/system/core/Exceptions.php b/system/core/Exceptions.php
index f565956..bff86a9 100644
--- a/system/core/Exceptions.php
+++ b/system/core/Exceptions.php
@@ -128,7 +128,7 @@
 			ob_end_flush();
 		}
 		ob_start();
-		include(APPPATH.'errors/'.$template.EXT);
+		include(APPPATH.'errors/'.$template.'.php');
 		$buffer = ob_get_contents();
 		ob_end_clean();
 		return $buffer;
@@ -164,7 +164,7 @@
 			ob_end_flush();
 		}
 		ob_start();
-		include(APPPATH.'errors/error_php'.EXT);
+		include(APPPATH.'errors/error_php.php');
 		$buffer = ob_get_contents();
 		ob_end_clean();
 		echo $buffer;
diff --git a/system/core/Hooks.php b/system/core/Hooks.php
index 24fa105..fd6380f 100644
--- a/system/core/Hooks.php
+++ b/system/core/Hooks.php
@@ -65,13 +65,13 @@
 		// Grab the "hooks" definition file.
 		// If there are no hooks, we're done.
 
-		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/hooks'.EXT))
+		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/hooks.php'))
 		{
-		    include(APPPATH.'config/'.ENVIRONMENT.'/hooks'.EXT);
+		    include(APPPATH.'config/'.ENVIRONMENT.'/hooks.php');
 		}
-		elseif (is_file(APPPATH.'config/hooks'.EXT))
+		elseif (is_file(APPPATH.'config/hooks.php'))
 		{
-			include(APPPATH.'config/hooks'.EXT);
+			include(APPPATH.'config/hooks.php');
 		}
 
 
diff --git a/system/core/Lang.php b/system/core/Lang.php
index cdadc7f..170e6c7 100644
--- a/system/core/Lang.php
+++ b/system/core/Lang.php
@@ -51,14 +51,14 @@
 	 */
 	function load($langfile = '', $idiom = '', $return = FALSE, $add_suffix = TRUE, $alt_path = '')
 	{
-		$langfile = str_replace(EXT, '', $langfile);
+		$langfile = str_replace('.php', '', $langfile);
 
 		if ($add_suffix == TRUE)
 		{
 			$langfile = str_replace('_lang.', '', $langfile).'_lang';
 		}
 
-		$langfile .= EXT;
+		$langfile .= '.php';
 
 		if (in_array($langfile, $this->is_loaded, TRUE))
 		{
diff --git a/system/core/Loader.php b/system/core/Loader.php
index e75805d..59415b7 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -161,7 +161,7 @@
 
 		foreach ($this->_ci_model_paths as $mod_path)
 		{
-			if ( ! file_exists($mod_path.'models/'.$path.$model.EXT))
+			if ( ! file_exists($mod_path.'models/'.$path.$model.'.php'))
 			{
 				continue;
 			}
@@ -181,7 +181,7 @@
 				load_class('Model', 'core');
 			}
 
-			require_once($mod_path.'models/'.$path.$model.EXT);
+			require_once($mod_path.'models/'.$path.$model.'.php');
 
 			$model = ucfirst($model);
 
@@ -217,7 +217,7 @@
 			return FALSE;
 		}
 
-		require_once(BASEPATH.'database/DB'.EXT);
+		require_once(BASEPATH.'database/DB.php');
 
 		if ($return === TRUE)
 		{
@@ -253,8 +253,8 @@
 		// this use is deprecated and strongly discouraged
 		$CI->load->dbforge();
 
-		require_once(BASEPATH.'database/DB_utility'.EXT);
-		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_utility'.EXT);
+		require_once(BASEPATH.'database/DB_utility.php');
+		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_utility.php');
 		$class = 'CI_DB_'.$CI->db->dbdriver.'_utility';
 
 		$CI->dbutil = new $class();
@@ -277,8 +277,8 @@
 
 		$CI =& get_instance();
 
-		require_once(BASEPATH.'database/DB_forge'.EXT);
-		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_forge'.EXT);
+		require_once(BASEPATH.'database/DB_forge.php');
+		require_once(BASEPATH.'database/drivers/'.$CI->db->dbdriver.'/'.$CI->db->dbdriver.'_forge.php');
 		$class = 'CI_DB_'.$CI->db->dbdriver.'_forge';
 
 		$CI->dbforge = new $class();
@@ -375,16 +375,16 @@
 				continue;
 			}
 
-			$ext_helper = APPPATH.'helpers/'.config_item('subclass_prefix').$helper.EXT;
+			$ext_helper = APPPATH.'helpers/'.config_item('subclass_prefix').$helper.'.php';
 
 			// Is this a helper extension request?
 			if (file_exists($ext_helper))
 			{
-				$base_helper = BASEPATH.'helpers/'.$helper.EXT;
+				$base_helper = BASEPATH.'helpers/'.$helper.'.php';
 
 				if ( ! file_exists($base_helper))
 				{
-					show_error('Unable to load the requested file: helpers/'.$helper.EXT);
+					show_error('Unable to load the requested file: helpers/'.$helper.'.php');
 				}
 
 				include_once($ext_helper);
@@ -398,9 +398,9 @@
 			// Try to load the helper
 			foreach ($this->_ci_helper_paths as $path)
 			{
-				if (file_exists($path.'helpers/'.$helper.EXT))
+				if (file_exists($path.'helpers/'.$helper.'.php'))
 				{
-					include_once($path.'helpers/'.$helper.EXT);
+					include_once($path.'helpers/'.$helper.'.php');
 
 					$this->_ci_helpers[$helper] = TRUE;
 					log_message('debug', 'Helper loaded: '.$helper);
@@ -411,7 +411,7 @@
 			// unable to load the helper
 			if ( ! isset($this->_ci_helpers[$helper]))
 			{
-				show_error('Unable to load the requested file: helpers/'.$helper.EXT);
+				show_error('Unable to load the requested file: helpers/'.$helper.'.php');
 			}
 		}
 	}
@@ -490,7 +490,7 @@
 		if ( ! class_exists('CI_Driver_Library'))
 		{
 			// we aren't instantiating an object here, that'll be done by the Library itself
-			require BASEPATH.'libraries/Driver'.EXT;
+			require BASEPATH.'libraries/Driver.php';
 		}
 
 		// We can save the loader some time since Drivers will *always* be in a subfolder,
@@ -616,7 +616,7 @@
 		if ($_ci_path == '')
 		{
 			$_ci_ext = pathinfo($_ci_view, PATHINFO_EXTENSION);
-			$_ci_file = ($_ci_ext == '') ? $_ci_view.EXT : $_ci_view;
+			$_ci_file = ($_ci_ext == '') ? $_ci_view.'.php' : $_ci_view;
 			$_ci_path = $this->_ci_view_path.$_ci_file;
 		}
 		else
@@ -732,7 +732,7 @@
 		// Get the class name, and while we're at it trim any slashes.
 		// The directory path can be included as part of the class name,
 		// but we don't want a leading slash
-		$class = str_replace(EXT, '', trim($class, '/'));
+		$class = str_replace('.php', '', trim($class, '/'));
 
 		// Was the path included with the class name?
 		// We look for a slash to determine this
@@ -749,12 +749,12 @@
 		// We'll test for both lowercase and capitalized versions of the file name
 		foreach (array(ucfirst($class), strtolower($class)) as $class)
 		{
-			$subclass = APPPATH.'libraries/'.$subdir.config_item('subclass_prefix').$class.EXT;
+			$subclass = APPPATH.'libraries/'.$subdir.config_item('subclass_prefix').$class.'.php';
 
 			// Is this a class extension request?
 			if (file_exists($subclass))
 			{
-				$baseclass = BASEPATH.'libraries/'.ucfirst($class).EXT;
+				$baseclass = BASEPATH.'libraries/'.ucfirst($class).'.php';
 
 				if ( ! file_exists($baseclass))
 				{
@@ -793,7 +793,7 @@
 			$is_duplicate = FALSE;
 			foreach ($this->_ci_library_paths as $path)
 			{
-				$filepath = $path.'libraries/'.$subdir.$class.EXT;
+				$filepath = $path.'libraries/'.$subdir.$class.'.php';
 
 				// Does the file exist?  No?  Bummer...
 				if ( ! file_exists($filepath))
@@ -872,24 +872,24 @@
 					// We test for both uppercase and lowercase, for servers that
 					// are case-sensitive with regard to file names. Check for environment
 					// first, global next
-					if (defined('ENVIRONMENT') AND file_exists($path .'config/'.ENVIRONMENT.'/'.strtolower($class).EXT))
+					if (defined('ENVIRONMENT') AND file_exists($path .'config/'.ENVIRONMENT.'/'.strtolower($class).'.php'))
 					{
-						include_once($path .'config/'.ENVIRONMENT.'/'.strtolower($class).EXT);
+						include_once($path .'config/'.ENVIRONMENT.'/'.strtolower($class).'.php');
 						break;
 					}
-					elseif (defined('ENVIRONMENT') AND file_exists($path .'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).EXT))
+					elseif (defined('ENVIRONMENT') AND file_exists($path .'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).'.php'))
 					{
-						include_once($path .'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).EXT);
+						include_once($path .'config/'.ENVIRONMENT.'/'.ucfirst(strtolower($class)).'.php');
 						break;
 					}
-					elseif (file_exists($path .'config/'.strtolower($class).EXT))
+					elseif (file_exists($path .'config/'.strtolower($class).'.php'))
 					{
-						include_once($path .'config/'.strtolower($class).EXT);
+						include_once($path .'config/'.strtolower($class).'.php');
 						break;
 					}
-					elseif (file_exists($path .'config/'.ucfirst(strtolower($class)).EXT))
+					elseif (file_exists($path .'config/'.ucfirst(strtolower($class)).'.php'))
 					{
-						include_once($path .'config/'.ucfirst(strtolower($class)).EXT);
+						include_once($path .'config/'.ucfirst(strtolower($class)).'.php');
 						break;
 					}
 				}
@@ -965,13 +965,13 @@
 	 */
 	function _ci_autoloader()
 	{
-		if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/autoload'.EXT))
+		if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/autoload.php'))
 		{
-			include_once(APPPATH.'config/'.ENVIRONMENT.'/autoload'.EXT);
+			include_once(APPPATH.'config/'.ENVIRONMENT.'/autoload.php');
 		}
 		else
 		{
-			include_once(APPPATH.'config/autoload'.EXT);
+			include_once(APPPATH.'config/autoload.php');
 		}
 		
 
@@ -1084,13 +1084,13 @@
 	{
 		if ( ! is_array($filename))
 		{
-			return array(strtolower(str_replace(EXT, '', str_replace($extension, '', $filename)).$extension));
+			return array(strtolower(str_replace('.php', '', str_replace($extension, '', $filename)).$extension));
 		}
 		else
 		{
 			foreach ($filename as $key => $val)
 			{
-				$filename[$key] = strtolower(str_replace(EXT, '', str_replace($extension, '', $val)).$extension);
+				$filename[$key] = strtolower(str_replace('.php', '', str_replace($extension, '', $val)).$extension);
 			}
 
 			return $filename;
diff --git a/system/core/Output.php b/system/core/Output.php
index 45a82f3..05ace91 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -42,13 +42,13 @@
 		$this->_zlib_oc = @ini_get('zlib.output_compression');
 
 		// Get mime types for later
-		if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT))
+		if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))
 		{
-		    include APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT;
+		    include APPPATH.'config/'.ENVIRONMENT.'/mimes.php';
 		}
 		else
 		{
-			include APPPATH.'config/mimes'.EXT;
+			include APPPATH.'config/mimes.php';
 		}
 
 
diff --git a/system/core/Router.php b/system/core/Router.php
index d451aab..5e92a04 100644
--- a/system/core/Router.php
+++ b/system/core/Router.php
@@ -87,13 +87,13 @@
 		}
 
 		// Load the routes.php file.
-		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/routes'.EXT))
+		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/routes.php'))
 		{
-			include(APPPATH.'config/'.ENVIRONMENT.'/routes'.EXT);
+			include(APPPATH.'config/'.ENVIRONMENT.'/routes.php');
 		}
-		elseif (is_file(APPPATH.'config/routes'.EXT))
+		elseif (is_file(APPPATH.'config/routes.php'))
 		{
-			include(APPPATH.'config/routes'.EXT);
+			include(APPPATH.'config/routes.php');
 		}
 		
 		$this->routes = ( ! isset($route) OR ! is_array($route)) ? array() : $route;
@@ -227,7 +227,7 @@
 		}
 
 		// Does the requested controller exist in the root folder?
-		if (file_exists(APPPATH.'controllers/'.$segments[0].EXT))
+		if (file_exists(APPPATH.'controllers/'.$segments[0].'.php'))
 		{
 			return $segments;
 		}
@@ -242,7 +242,7 @@
 			if (count($segments) > 0)
 			{
 				// Does the requested controller exist in the sub-folder?
-				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].EXT))
+				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].'.php'))
 				{
 					show_404($this->fetch_directory().$segments[0]);
 				}
@@ -264,7 +264,7 @@
 				}
 
 				// Does the default controller exist in the sub-folder?
-				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.EXT))
+				if ( ! file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.'.php'))
 				{
 					$this->directory = '';
 					return array();