Shoutbox

Windows Scripting Host (or maybe its called ActiveX scripting and is just used by the WSH, not too sure on that point) is just using the MS scripting engine, you give it the script, some bindings (COM objects) and a language ID (VBScript, JScript, ...) and then you set it off. If you were going to use the normal VBScript engine (and not write your own) then the difference should be about as profound as giving a language ID when you run the script.

VBScript and JScript are both installed by default (the only ones that are), so are a good choice to support. I think PerlScript and others should be an option for those who want that kind of thing, just make sure you don't advertise it too heavily and don't bundle any non JS/VB scripts.

I prefer JScript over VBScript because JScript has far better array/dictionary support integrated directly in, it is cross platform and a standard (EMCAScript) - you can use it in Netscape/Opera, the string manipulation methods are better, it shares all the keywords/semantics with C++ (useful for you). Also classes, memory allocation and dynamic functions were added in far earlier versions, and not all of them are present yet present in VBScript. However, they are both just as powerful, its merely my preference.