If the QuickTime to the left does not play, you need to download the QuickTime plugin from Apple, linked below in the "Useful Software" section. QuickTime is free unless you wish to upgrade to the Pro version, which makes more playback options available as well as adds features for media creators.

Note: QuickTime does not display a download progress bar. This is normal. As long as you see the QuickTime logo appear, the plugin is recognized. If you're using IE for Windows and you're sure you have QuickTime installed, but no movie appears, make sure you have not blocked ActiveX -- it is required in IE 5.5SP2 and later.