Joomla is a free, open source and very powerful CMS (Content Management System). You need webspace which supports PHP and gives you a SQL database. Most and even cheap packages from webhosters offer this.

The beauty of the system is that as soon it is installed and the website is designed it is very easy to upload new content via a webbrowser. So it is platform inddependent.

You can find Joomla here Joomla Website