Detection in Internet Explorer seems a little harder than detection in Netscape Navigator, because IE doens't have the plugins object. It can be done much easier by calling a VBScript function from javascript. This way we have a clean and simple way to detect all kinds of ActiveX controls that are installed on the users system. This is an object that I picked up from a browser sniffer article by Netscape. It can detect the internetbrowser an the OS of your visitor.
Caps object .
This object can be used to detect what capabilities the browser of your visitor has. It handles the differences between the specific browsers. Including vrml detection in your pages You can include VRML plug-in detection by following these simple steps. For example use caps.vrml to detect if your visitor has a VRML browser installed. Take a look at this example that dumps al variables and their values.