What is the Visio Viewer?
The Visio viewer is freely available from Microsoft. If your co-workers and customers don’t have Visio installed, they can install the viewer, then view and interact with Visio drawings that you send them in a browser or in Outlook. If they have Outlook 2007, then they may already have the viewer installed, because Outlook 2007 installs the Visio 2007 viewer by default. With the viewer, they can pan and zoom, switch pages, view Shape Data (Custom Properties), turn layers on and off, and view or hide annotations.