The ThingViewer plug-in works with the Windows operating system and both the Netscape browser and Microsoft's Internet Explorer.
I'm not sure if it works with any other operating system or other browsers.
Get the ThingViewer plug-in here - ThingViewer version 1.60
This installer file has been zipped using WinZip since Geocities doesn't allow exe files. After downloading the zip file, unzip it using a program such as WinZip. Then double-click the self-extracting exe file which will install the ThingViewer plug-in.
If successful you should be able to view the ThingWorld logo on this page. You may need to click the refresh/reload button.
SPECIAL THANKS TO
Unfortunately, ThingWorld has gone out of business. The website and its automatic plug-in are no longer available.
However, all creations (on and off this website) can be accessed by installing the ThingViewer program via the link posted above.