PHP 4.3 but PHP 5.0 recommended
Apache Web Server
MySQL or PostgreSQL
If you have a web hosting account for your web site, the simplest way is to upload Radria on your web site.
If you want to run Radria on your own computer you will need to install a LAMP server.
We can suggest xampp
it works for Windows, Linux and Mac OS X.
For windows we can also suggest the The Uniform Server
its much smaller than XAMPP (7MB).