SVG stands for Scalable Vector Graphics, a new web standard created under the watchful eyes of the World Wide Web Consortium, who is the body which oversees new web standards.
Since SVG is a new standard, few browsers support viewing SVGs directly, though this should be changing fairly soon. Currently, only the latest release of the Mozilla browser supports it.
If you don't have or want to install Mozilla, a small Plug-In for both Internet Explorer and Netscape is available from Adobe. A copy of the Adobe SVG Viewer installation media can be found on this CDROM by clicking here.
There are several ways to scale the image. First, right clicking inside the image will give you a pop-up menu with several selections on it, including zoom in/out. The second method is to hold down the CTRL-key down, the mouse icon will turn into a magnifying glass with a plus (+) in it. Left clicking will zoom in centered on the spot you click. SHIFT-CTRL-left click will unzoom with that spot as the center. You can also CTRL-left-click-drag a box around the area you want to view,and the image will be zoomed into that area.
To move your viewpoint around the image, especially helpful when zoomed in close, hold the ALT-key down and the icon will turn into a hand. "Grab" the image by left clicking and drag the image to the desired location.