From Silhouette America:
Silhouette Studio software gives you the ability to design projects to send to any Silhouette electronic cutting machine. The basic edition of Silhouette Studio is included with the purchase of each Silhouette and can also be downloaded for free from www.silhouetteamerica.com/software/silhouette-studio. You can download Silhouette Studio even if you don't have a Silhouette electronic cutting machine yet. That way you can practice creating projects using the software's design tools and the fonts on your computer. You can also build up your library and take advantage of Silhouette Online Store sales and promotions. You can even begin collecting the weekly free shapes to use once you finally get your Silhouette.
Version 3.6.057: Registration mark thickness now defaults to 0.020 inch for improved registration mark reading. Older documents will retain their previously set value unless the "Restore Defaults" button is pressed.