Server Side: Anything. FusionCharts Free runs on Windows, Linux, Unix or any other imaginable form of server that you can think of. Just make sure that your server MIME is configured for SWF files to ensure proper streaming. Most servers come pre-configured for SWF files.

Client Side: Adobe Flash Player 6 (or above). Adobe Flash Player is a free and light-weight plugin to render Flash movies. It can be downloaded from www.adobe.com. It's one of the most widely installed plugin on this planet.