As of the latest versions of IE, there is no longer any support for Netscape-style plugins. Fair enough I suppose, as Netscape never bothered to include ActiveX support in their browser.
The result of this, is that the Xara plugin won't work for IE users in Windows XP, or on any systems that keep their IE browsers up to date.
Apple's Quicktime had this problem for a while, but they just released a fix for it (Apple's QT Fix). (An ActiveX control that can load the Quicktime plugin.)
Maybe Xara will be able to follow suit. I've noticed a number of personal sites that use the WEB format, so this will definately affect them.
Do many people use this format? Or is the need for the viewer to download the extra plugin more effort than most web surfers can handle?
I guess that we need to justify the extra development to fix this problem, by showing Xara that the plugin's benefits outweigh it's costs.