If you need a Browser Language Detection for your Coding, try this. At the end it come stored in a Session.

< ? php
  function lixlpixel_get_env_var($Var)
    {
      if (empty($GLOBALS[$Var]))
        {
          $GLOBALS[$Var] = (!empty($GLOBALS['_SERVER'][$Var])) ? $GLOBALS['_SERVER'][$Var] : (!empty($GLOBALS['HTTP_SERVER_VARS'][$Var])) ? $GLOBALS['HTTP_SERVER_VARS'][$Var] : ”;
        }
    }
  
  function lixlpixel_detect_lang()
    {
      // Detect HTTP_ACCEPT_LANGUAGE & HTTP_USER_AGENT.
      lixlpixel_get_env_var(‘HTTP_ACCEPT_LANGUAGE’);
      lixlpixel_get_env_var(‘HTTP_USER_AGENT’);
      
      $_AL = strtolower($GLOBALS['HTTP_ACCEPT_LANGUAGE']);
      $_UA = strtolower($GLOBALS['HTTP_USER_AGENT']);
      
      // Try to detect Primary language if several languages are accepted.
      foreach ($GLOBALS['_LANG'] as $K)
        {
          if (strpos($_AL, $K) === 0)
              return $K;
        }
      
      // Try to detect any language if not yet detected.
      foreach ($GLOBALS['_LANG'] as $K)
        {
          if (strpos($_AL, $K) !== false)
              return $K;
        }
      foreach ($GLOBALS['_LANG'] as $K)
        {
          if (preg_match(“/[\[\( ]{$K}[;,_\-\)]/”, $_UA))
              return $K;
        }
      
      // Return default language if language is not yet detected.
      return $GLOBALS['_DLANG'];
    }
  
  // Define default language.
  $GLOBALS['_DLANG'] = ‘en’;
  
  // Define all available languages.
  // WARNING: uncomment all available languages
  
  $GLOBALS['_LANG'] = array(‘af’, // afrikaans.
  ‘ar’, // arabic.
  ‘bg’, // bulgarian.
  ‘ca’, // catalan.
  ‘cs’, // czech.
  ‘da’, // danish.
  ‘de’, // german.
  ‘el’, // greek.
  ‘en’, // english.
  ‘es’, // spanish.
  ‘et’, // estonian.
  ‘fi’, // finnish.
  ‘fr’, // french.
  ‘gl’, // galician.
  ‘he’, // hebrew.
  ‘hi’, // hindi.
  ‘hr’, // croatian.
  ‘hu’, // hungarian.
  ‘id’, // indonesian.
  ‘it’, // italian.
  ‘ja’, // japanese.
  ‘ko’, // korean.
  ‘ka’, // georgian.
  ‘lt’, // lithuanian.
  ‘lv’, // latvian.
  ‘ms’, // malay.
  ‘nl’, // dutch.
  ‘no’, // norwegian.
  ‘pl’, // polish.
  ‘pt’, // portuguese.
  ‘ro’, // romanian.
  ‘ru’, // russian.
  ’sk’, // slovak.
  ’sl’, // slovenian.
  ’sq’, // albanian.
  ’sr’, // serbian.
  ’sv’, // swedish.
  ‘th’, // thai.
  ‘tr’, // turkish.
  ‘uk’, // ukrainian.
  ‘zh’ // chinese.);
  
  // Redirect to the correct location.
  
  //header(‘location: http://www.your_site.com/index_’.lixlpixel_detect_lang().’.php’); // Example Implementation
  //echo ’The Language detected is: ’.lixlpixel_detect_lang(); // For Demonstration
  
  
  function setautolang()
    {
      // start up your PHP session!
      session_start();
      
      $sprache = lixlpixel_detect_lang();
      
      if ($sprache == “de”)
        {
          $_SESSION['lang'] = “deutsch”;
        }
      elseif ($sprache == “en”)
        {
          $_SESSION['lang'] = “english”;
        }
      elseif ($sprache == “cs”)
        {
          $_SESSION['lang'] = “tschechisch”;
        }
      elseif ($sprache == “ru”)
        {
          $_SESSION['lang'] = “russian”;
        }
      elseif ($sprache == “it”)
        {
          $_SESSION['lang'] = “italian”;
        }
      else
        {
          $_SESSION['lang'] = “english”;
        }
    }
?>

Sometimes you have some complex Echo and in your String are  ’ or ” and you may come quit crazy with the delimeter of it  like:  echo “<a href=”goto.htm”>test</a>”.  Already you would created an Error by including ” in “”. Now you can choose to make outside ‘ or Inside. But when the Echo comes more complex, you may get some Headache where to use ” and where ‘ and where `

For that Reason you can write your Output for the Echo in <<< label  (your content)  label; and all is done.

<?php

echo <<< _end_this

Just a Demo to see, that you can include ‘ or ” or ` in your Output without Problem.<br>Like for Standart Html Commands as <a href=”test.htm”><b>test</b></a><br> and so on

_end_this;

?>

When you like really like to code as a pro you should take care on the Optimiziation of your Code. You can speed up your Code by Factor 7, just by taking care on a few Hints.

For example when you look for Scalability you have to make much more compromises instead when you look to speed up your Code.

Especialy when you expect a lot of Traffic you always should look for speed. What is the best System when it is too slow. Just remember your own acting in the Net, when a Page is too slow, you just leave it.

Here I collected you some of the most interesting Tips about that Topic. 

I researched within the following Resources: 

http://www.Cluesheet.com
http://www.chazzuka.com/blog/?p=163
http://reinholdweber.com/?p=3
http://phplens.com/lens/php-book/optimizing-debugging-php.php
http://www.phpbuilder.com/columns/weerning20021209.php3?print_mode=1 

Thanks to all the Coders before me, who collected already quit a lot of that Information.

Sometimes you may need to protect your PHP Code. For example when you like to monetize it. For that reason I searched for Applications that help to solve that case and found one Product that works quit fast and does not need any extra Loader. Just Decode any PHP Code and upload it to your Server instead of the Original Code.

TrueBug PHP Obfuscator & Encoder is for PHP application developers use to protect their source codes from modification, the Obfuscate functional will replace class, function, and variable names in PHP source codes with md5-hashes, making source code harder to understand and reverse engineering. The Software also includes simple PHP Encoder engine to encode through the source code by using byte-code technique, and no loader is required to install on the server machine.

Features:

• Friendly user interface, developers can easily select files to be obfuscated and encoded, can select which classes, functions, and variables to be included or excluded from obfuscation.
• Run scripts under virtual hosting accounts with no change to the default PHP installation and require no changes to the standard web server installation.
• Free minor upgrades

System Requirements:

• 750 MHz CPU with minimum 256 MB of RAM
• Windows 2000/XP/2003/Vista

How to validate URLs by a small RegEx Function:

function valid_url($str) {
return (!preg_match(‘/^(http|https|ftp):\/\/([A-Z0-9][A-Z0-9_-]*(?:\.[A-Z0-9][A-Z0-9_-]*)+):?(\d+)?\/?/i’, $str)) ? FALSE : TRUE;
}

And how does it work:

^ is an anchor meaning it must start with the pattern
(http|https|ftp) matches and captures one of the three
:\/\/ is :// literally. (\/ is / escaped)
([A-Z0-9][A-Z0-9_-]*(?:\.[A-Z0-9][A-Z0-9_-]*)+)

(letter meaning a-z in the following)

1 letter or number
any number of letters, numbers, _ or -.
A literal dot
1 letter or number
any number of letters, numbers, _ or -.
+ means the previous pattern 1 or more times, and the grouping is around (?:\.[A-Z0-9][A-Z0-9_-]*)+, so it means that pattern any number of times. (It allows for .co.uk for example. )

(\d+)?\/?/i
0-1 :
Any amount of digits
An optional literal /

You may also like this Tutorial for regular Expressions:
>>Regular Expression Tutorial