The PHP extension ZendOptimizer is installed on all of our shared hosting servers by default. If you want to check the ZendOptimizer version, please create a PHP script on your account with the following content:
<?php phpinfo(); ?>
The access the file via your browser and it will show you the entire configuration of the PHP interpreter as well as the ZendOptimizer version.
If you have a script that gives an error about missing ZendOptimizer, please make sure you are not using any custom php.ini files. When you have a custom php.ini file, it overwrites the global PHP settings and this may result in a missing ZendOptimizer script error.