ZendOptimizer installation on Linux

1. Check PHP version of the Linux server.
2. Download ZendOptimizer: http://www.zend.com/en/products/guard/downloads
3. Follow the instruction of '1&1':
   http://faq.1and1.com/scripting_languages_supported/php/15.html
   
4. After unzipping, you might write a 'php.info' file on the folder where ZendOptimizer was installed.
   
   * If you want to see whether the ZendOptimizer was installed successfully, check with 'php.info' and 'test_enc.php'.

* About setting PHP global variables with php.ini:
http://faq.1and1.com/scripting_languages_supported/php/9.html