STRATO packages EasyWeb and higher include PHP versions 3, 4.x and 5.
To find out which version has been installed on the server simply create a text file entitled:

info.php.
Open a text editor program (e.g. in Windows, click Start -> Programs -> Accessories) then "Editor" or "WordPad").
Then type the following text:
<?php
phpinfo();
?>
Save this file as

info.php and upload it using your FTP program to the main (root) directory of your webspace.

If you have saved the file as

info.php.txt then you will have to rename it before uploading it.
When the file has been uploaded, open your browser and enter the following address:
http://www.yourstratodomain.eu/info.php.
(please be sure to replace "yourstratodomain.eu" with your actual domain name)
This script will then display your current PHP settings in your browser window.
For security reasons, we advise you to delete this file when have finished using it.