diff --git a/README b/README
index c7215ab1..9304219b 100644
--- a/README
+++ b/README
@@ -120,7 +120,7 @@ $smarty->unregisterObject($object_name)
 $smarty->unregisterFilter($type, $function_name)
 $smarty->unregisterResource($resource_type)
 
-$smarty->compileAllTemplates($extention = '.tpl', $force_compile = false, $time_limit = 0, $max_errors = null)
+$smarty->compileAllTemplates($extension = '.tpl', $force_compile = false, $time_limit = 0, $max_errors = null)
 $smarty->clearCompiledTemplate($resource_name = null, $compile_id = null, $exp_time = null)
 $smarty->testInstall()
 
diff --git a/SMARTY_3.1_NOTES.txt b/SMARTY_3.1_NOTES.txt
index e56e56f6..57709f0d 100644
--- a/SMARTY_3.1_NOTES.txt
+++ b/SMARTY_3.1_NOTES.txt
@@ -199,7 +199,7 @@ Relative paths are available with {include file="..."} and
 $smarty->fetch('./foo.tpl') cannot be relative to a template, an
 exception is thrown.
 
-  Adressing a specific $template_dir
+  Addressing a specific $template_dir
 
 Smarty 3.1 introduces the $template_dir index notation.
 $smarty->fetch('[foo]bar.tpl') and {include file="[foo]bar.tpl"}
diff --git a/change_log.txt b/change_log.txt
index f74f59d4..0345167a 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -1,4 +1,7 @@
 ===== trunk  =====
+17.06.2013
+- fixed spelling in sources and documentation (from smarty-developers forum Veres Lajos)
+
 26.05.2013
 - enhancement an expire_time of -1 in clearCache() and clearAllCache() will delete outdated cache files
   by their individual cache_lifetime used at creation (forum topic 24310)
@@ -442,7 +445,7 @@
 03/09/2011
 - bugfix createTemplate() must default to cache_id and compile_id of Smarty object
 - bugfix Smarty_CacheResource_KeyValueStore must include $source->uid in cache filepath to keep templates with same
-  name but different folders seperated
+  name but different folders separated
 - added cacheresource.apc.php example in demo folder
 
 02/09/2011
@@ -633,7 +636,7 @@
 - changed ./ and ../ behaviour
 
 14/02/2011
-- added {block ... hide} option to supress block if no child is defined
+- added {block ... hide} option to suppress block if no child is defined
 
 13/02/2011
 - update handling of recursive subtemplate calls
@@ -747,7 +750,7 @@
 - bugfix on compiler object destruction. compiler_object property was by mistake unset.
 
 09/03/2011
--bugfix a variable filter should run before modifers on an output tag (see change of 23/07/2010)
+-bugfix a variable filter should run before modifiers on an output tag (see change of 23/07/2010)
 
 08/03/2011
 - bugfix loading config file without section should load only defaults
@@ -1051,10 +1054,10 @@ request_use_auto_globals
 - bugfix passing scope attributes in doublequoted strings did not work at {include} {assign} and {append}
 
 25/07/2010
-- another bugfix of change from 23/07/2010 when compiling modifer
+- another bugfix of change from 23/07/2010 when compiling modifier
 
 24/07/2010
-- bugfix of change from 23/07/2010 when compiling modifer
+- bugfix of change from 23/07/2010 when compiling modifier
 
 23/07/2010
 - changed execution order. A variable filter does now run before modifiers on output of variables
@@ -1361,7 +1364,7 @@ request_use_auto_globals
 - bugfix on {if} tags 
 
 01/12/2010
-- changed back modifer handling in parser. Some restrictions still apply:
+- changed back modifier handling in parser. Some restrictions still apply:
     if modifiers are used in side {if...} expression or in mathematical expressions 
     parentheses must be used.
 - bugfix the {function..} tag did not accept the name attribute in double quotes
@@ -1973,7 +1976,7 @@ NOTICE: existing compiled template and cache files must be deleted
 - fixed exceptions in function plugins
 - fixed notice error in Smarty.class.php
 - allow chained objects to span multiple lines
-- fixed error in modifers 
+- fixed error in modifiers 
 
 03/20/2009
 - moved /plugins folder into /libs folder
@@ -1981,7 +1984,7 @@ NOTICE: existing compiled template and cache files must be deleted
 - autoappend a directory separator if the xxxxx_dir definition have no trailing one
 
 03/19/2009
-- allow array definition as modifer parameter
+- allow array definition as modifier parameter
 - changed modifier to use multi byte string funktions. 
 
 03/17/2009
diff --git a/demo/plugins/resource.mysqls.php b/demo/plugins/resource.mysqls.php
index f9fe1c2f..e22bed0a 100644
--- a/demo/plugins/resource.mysqls.php
+++ b/demo/plugins/resource.mysqls.php
@@ -7,7 +7,7 @@
  * MySQL as the storage resource for Smarty's templates and configs.
  *
  * Note that this MySQL implementation fetches the source and timestamps in
- * a single database query, instead of two seperate like resource.mysql.php does.
+ * a single database query, instead of two separate like resource.mysql.php does.
  *
  * Table definition:
  * <pre>CREATE TABLE IF NOT EXISTS `templates` (
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index 883d12a3..2b9f795e 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -1323,9 +1323,9 @@ class Smarty extends Smarty_Internal_TemplateBase {
      * @param int $max_errors
      * @return integer number of template files recompiled
      */
-    public function compileAllTemplates($extention = '.tpl', $force_compile = false, $time_limit = 0, $max_errors = null)
+    public function compileAllTemplates($extension = '.tpl', $force_compile = false, $time_limit = 0, $max_errors = null)
     {
-        return Smarty_Internal_Utility::compileAllTemplates($extention, $force_compile, $time_limit, $max_errors, $this);
+        return Smarty_Internal_Utility::compileAllTemplates($extension, $force_compile, $time_limit, $max_errors, $this);
     }
 
     /**
@@ -1337,9 +1337,9 @@ class Smarty extends Smarty_Internal_TemplateBase {
      * @param int $max_errors
      * @return integer number of template files recompiled
      */
-    public function compileAllConfig($extention = '.conf', $force_compile = false, $time_limit = 0, $max_errors = null)
+    public function compileAllConfig($extension = '.conf', $force_compile = false, $time_limit = 0, $max_errors = null)
     {
-        return Smarty_Internal_Utility::compileAllConfig($extention, $force_compile, $time_limit, $max_errors, $this);
+        return Smarty_Internal_Utility::compileAllConfig($extension, $force_compile, $time_limit, $max_errors, $this);
     }
 
     /**
diff --git a/libs/sysplugins/smarty_cacheresource.php b/libs/sysplugins/smarty_cacheresource.php
index ca18add5..a6852998 100644
--- a/libs/sysplugins/smarty_cacheresource.php
+++ b/libs/sysplugins/smarty_cacheresource.php
@@ -224,7 +224,7 @@ class Smarty_Template_Cached {
     public $timestamp = false;
 
     /**
-    * Source Existance
+    * Source Existence
     * @var boolean
     */
     public $exists = false;
diff --git a/libs/sysplugins/smarty_internal_templatecompilerbase.php b/libs/sysplugins/smarty_internal_templatecompilerbase.php
index 0928d80d..8b5140cd 100644
--- a/libs/sysplugins/smarty_internal_templatecompilerbase.php
+++ b/libs/sysplugins/smarty_internal_templatecompilerbase.php
@@ -607,7 +607,7 @@ abstract class Smarty_Internal_TemplateCompilerBase {
                 $_output = addcslashes($content,'\'\\');
                 $_output = str_replace("^#^", "'", $_output);
                 $_output = "<?php echo '/*%%SmartyNocache:{$this->nocache_hash}%%*/" . $_output . "/*/%%SmartyNocache:{$this->nocache_hash}%%*/';?>\n";
-                // make sure we include modifer plugins for nocache code
+                // make sure we include modifier plugins for nocache code
                 foreach ($this->modifier_plugins as $plugin_name => $dummy) {
                     if (isset($this->template->required_plugins['compiled'][$plugin_name]['modifier'])) {
                         $this->template->required_plugins['nocache'][$plugin_name]['modifier'] = $this->template->required_plugins['compiled'][$plugin_name]['modifier'];
diff --git a/libs/sysplugins/smarty_internal_utility.php b/libs/sysplugins/smarty_internal_utility.php
index f19ca01f..0bec8db1 100644
--- a/libs/sysplugins/smarty_internal_utility.php
+++ b/libs/sysplugins/smarty_internal_utility.php
@@ -58,7 +58,7 @@ class Smarty_Internal_Utility {
      * @param Smarty $smarty        Smarty instance
      * @return integer number of template files compiled
      */
-    public static function compileAllTemplates($extention, $force_compile, $time_limit, $max_errors, Smarty $smarty)
+    public static function compileAllTemplates($extension, $force_compile, $time_limit, $max_errors, Smarty $smarty)
     {
         // switch off time limit
         if (function_exists('set_time_limit')) {
@@ -74,7 +74,7 @@ class Smarty_Internal_Utility {
             foreach ($_compile as $_fileinfo) {
                 $_file = $_fileinfo->getFilename();
                 if (substr(basename($_fileinfo->getPathname()),0,1) == '.' || strpos($_file, '.svn') !== false) continue;
-                if (!substr_compare($_file, $extention, - strlen($extention)) == 0) continue;
+                if (!substr_compare($_file, $extension, - strlen($extension)) == 0) continue;
                 if ($_fileinfo->getPath() == substr($_dir, 0, -1)) {
                    $_template_file = $_file;
                 } else {
@@ -122,7 +122,7 @@ class Smarty_Internal_Utility {
      * @param Smarty $smarty        Smarty instance
      * @return integer number of config files compiled
      */
-    public static function compileAllConfig($extention, $force_compile, $time_limit, $max_errors, Smarty $smarty)
+    public static function compileAllConfig($extension, $force_compile, $time_limit, $max_errors, Smarty $smarty)
     {
         // switch off time limit
         if (function_exists('set_time_limit')) {
@@ -138,7 +138,7 @@ class Smarty_Internal_Utility {
             foreach ($_compile as $_fileinfo) {
                 $_file = $_fileinfo->getFilename();
                 if (substr(basename($_fileinfo->getPathname()),0,1) == '.' || strpos($_file, '.svn') !== false) continue;
-                if (!substr_compare($_file, $extention, - strlen($extention)) == 0) continue;
+                if (!substr_compare($_file, $extension, - strlen($extension)) == 0) continue;
                 if ($_fileinfo->getPath() == substr($_dir, 0, -1)) {
                     $_config_file = $_file;
                 } else {
@@ -308,7 +308,7 @@ class Smarty_Internal_Utility {
         foreach($smarty->getTemplateDir() as $template_dir) {
             $_template_dir = $template_dir;
             $template_dir = realpath($template_dir);
-            // resolve include_path or fail existance
+            // resolve include_path or fail existence
             if (!$template_dir) {
                 if ($smarty->use_include_path && !preg_match('/^([\/\\\\]|[a-zA-Z]:[\/\\\\])/', $_template_dir)) {
                     // try PHP include_path
@@ -429,7 +429,7 @@ class Smarty_Internal_Utility {
         foreach($smarty->getPluginsDir() as $plugin_dir) {
             $_plugin_dir = $plugin_dir;
             $plugin_dir = realpath($plugin_dir);
-            // resolve include_path or fail existance
+            // resolve include_path or fail existence
             if (!$plugin_dir) {
                 if ($smarty->use_include_path && !preg_match('/^([\/\\\\]|[a-zA-Z]:[\/\\\\])/', $_plugin_dir)) {
                     // try PHP include_path
@@ -561,7 +561,7 @@ class Smarty_Internal_Utility {
         foreach($smarty->getConfigDir() as $config_dir) {
             $_config_dir = $config_dir;
             $config_dir = realpath($config_dir);
-            // resolve include_path or fail existance
+            // resolve include_path or fail existence
             if (!$config_dir) {
                 if ($smarty->use_include_path && !preg_match('/^([\/\\\\]|[a-zA-Z]:[\/\\\\])/', $_config_dir)) {
                     // try PHP include_path
diff --git a/libs/sysplugins/smarty_resource.php b/libs/sysplugins/smarty_resource.php
index 55f1497f..0a563dfc 100644
--- a/libs/sysplugins/smarty_resource.php
+++ b/libs/sysplugins/smarty_resource.php
@@ -584,7 +584,7 @@ abstract class Smarty_Resource {
  * @author Rodney Rehm
  *
  * @property integer $timestamp Source Timestamp
- * @property boolean $exists    Source Existance
+ * @property boolean $exists    Source Existence
  * @property boolean $template  Extended Template reference
  * @property string  $content   Source Content
  */
@@ -811,7 +811,7 @@ class Smarty_Template_Compiled {
     public $timestamp = null;
 
     /**
-     * Compiled Existance
+     * Compiled Existence
      * @var boolean
      */
     public $exists = false;
diff --git a/libs/sysplugins/smarty_security.php b/libs/sysplugins/smarty_security.php
index f8b31d96..58f33787 100644
--- a/libs/sysplugins/smarty_security.php
+++ b/libs/sysplugins/smarty_security.php
@@ -77,7 +77,7 @@ class Smarty_Security {
         'nl2br',
     );
     /**
-     * This is an array of trusted PHP modifers.
+     * This is an array of trusted PHP modifiers.
      *
      * If empty all modifiers are allowed.
      * To disable all modifier set $modifiers = null.