Yes, it uses JScript. But JScript is the JavaScript language - it is Microsoft's implementation of JavaScript / ECMAScript.

For example if you get a book on programming "JavaScript", you can use it as a reference for programming "JScript" as well, they are the same specification.

You could use VBScript if you want for script files, just use the .vbs file extensio for the script file. But JScript is used for little script fragments that are not in their own file, like a script: keyboard shortcut.

- Michael