From FestOS wiki

FestOS runs on a Linux or Windows web server running either Apache or IIS. FestOS requires the following:

Core System Requirements

• PHP version 5.x+ with these options:
  • GD2 module enabled
  • php_curl module enabled for PayPal and Authorize.net payment modules
  • allow_url_fopen = On (enabled) for PayPal payment module
  • Register global off - Like many PHP-based applications, FestOS will be vulnerable to several forms of attack if register globals is left on.
  • Safe mode off
  • File uploads permitted
• MySQL 4.x+
• Approx. 15 MB free space for the FestOS files
• Any modern browser (Firefox, Chrome, Safari, Internet Explorer 7/8, etc.) with JavaScript enabled and cookies accepted (used to enable logging on).

Additionally, you will need to set a couple of directories and their contents to be writable by PHP. On Windows/IIS this is automatic. On Linux, you will need to set 777 permissions.

You might be able to run FestOS on a PHP 4 system, but you won't be able to use the PayPal or Authorize.net modules.

Real World Storage Space Requirements

Database space: Most of the data for your site will be stored in your database. Yet that information takes up very little room. An active FestOS database, storing the information for a couple of hundred applicants will consume only a few MB of MySQL database space.

Disk space: Applicants to your festival will be prompted to upload up to four digital photos. Small "thumbnail" versions of those photos are created and stored on your web server. Some reports also create temporary, smaller versions of those photos. One (1) MB of disk space per applicant is usually sufficient and typically you will require only about half that.

In addition, you will need space to store your web pages, templates, images, photos, PDF application forms, etc. that are not part of the FestOS system. In sum, a hosting package offering 100-200 MB of disk space is probably sufficient.

Further Information

Main FestOS Page : Installation : Customization  : Configuration : Administration : Payment Modules