Archive is a Netscape specific parameter that tells the browser to download a zip file and uses the classes that are stored in that. Width and height give the overall dimensions of the applet. If your GIS Viewer web page resides on the Berkeley Digital Library server then the applet tag should look very much like the HTML above. Where three dots are is where the rest of the parameters for the viewer go. These include general parameters, and parameters that describe specific layers and can get quite complex.
Parameters are fairly simple at the moment.
Minscale and maxscale give the valid range for the scale values. The bgcolor is the background color of the main viewing area.