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System requirements

Quam Plures is a web application, and for that it must be installed/hosted on a web server. If you do not have a web server yet, you have to find yourself one. If you already have a web server, here is what you need to check to make sure it can support Quam Plures:

Technical Requirements

Although most people will run Quam Plures on Linux with the [http://www.apache.org/ Apache] web server, those are not required set-ups. It is possible, for example, to run Quam Plures on Windows with the IIS web server. Your web server will also need to have:

  • PHP version 5.x.
  • MySQL version 5.x.

You can install Quam Plures in an already existing database as well as put several Quam Plures installations in one database. If your web server doesn't meet these specifications, we urge you to ask your web hosting provider to upgrade to PHP 5.x and MySQL 5.x. Otherwise, you can always switch to a better host.


Please note some hosting providers act paranoid when hosting PHP applications. As a matter of fact, they may degrade PHP itself, removing essential features such as file access, sockets (for connection to external sites), uploading files, sending emails or other features. Some features of Quam Plures may not work on such hosts. Quam Plures may not even be able to run at all. If your hosting provider shows such problems, we suggest you switch to another host.


PHP Memory Limit

Quam Plures requires more than the default of 8MB of memory. To change it, set the "memory_limit" php.ini value to a proper value, E.g. 16M.
In /conf/_advanced.php add the following line: ini_set('memory_limit', '16M');
Note: It is recommended to set this value in php.ini or .htaccess (for Apache) itself. If PHP is running in '''safe mode''', using ini_set() to bump the memory limit seems to have no effect. In such a situation, you should ask your web hosting provider to provide the correct values.

PHP Version

PHP Version 5.x is required.

PHP Modules

XML-RPC related functions and XHTML validation require the PHP XML module.

PHP Info

Please be sure to run a PHP info command on your server or ask your prospective hosting provider to do it and send you the output of the command. This will give you a variety of useful information, including the version of PHP that is installed on the server. You will also be able to see if you have the necessary PHP modules installed. Sample phpinfo.php file: Create and upload this file to your web server. Once you have uploaded it to your server, you will need to browse to it with your web browser. Your prospective hosting provider can tell you which version of PHP, Zend, or other software is being used on their system.

PHP Related Dependencies

Make sure that *if* (not all hosting providers use it) your PHP info says anything about a Zend Optimizer, that the version is 2.6.2 or newer. That means that 2.6.3 is fine but 2.6.1 is not. You will also want to make sure that your Zend Engine is newer than 1.3. The reason for this is that the older versions have bugs in them which cause this software package not to perform properly in certain circumstances. As of today, January 14, 2008, Zend Core 2.5, Zend Framework 1.0.3 and Zend Optimizer 3.3 are current. Zend Engine is now at version 2 in PHP 5. PHP's current version is 5.2.5.


The back-office uses CSS (style sheets) for layout and display. Older and experimental browsers, which do not handle CSS correctly will have display problems. Quam Plures is tested with the following browsers:

  • Firefox 3.0+
  • Internet Explorer 7.0
  • Chrome 3.5+
  • Safari 4.x

Browsers that are known to have display issues are given below:

  • Safari
  • Internet explorer 6.x
  • Mozilla 1.2
  • Netscape 4

Most of the time these issues can be solved by hacking the CSS file(s). If you come up with such solutions, we would appreciate it if you would please contribute them to the project.


*Quam Plures uses a DB abstraction class, which makes it easier to port the system to another DBMS.