Note that Microsoft has very recently unveiled JScript version 2.0. Due to the newness of version 2.0, this article strictly compares JScript 1.0 with Netscape's JavaScript 1.1. Almost all current users of Microsoft Explorer 3.0 or 3.01 are running JScript version 1.0. JScript 2.0 deserves a discussion of its own, which I hope to write about in a follow-up article, when more information about it becomes available. General Differences Microsoft's JScript 1.0 was designed to be compatible with Netscape's JavaScript.
Many differences stem from implementation bugs while other differences are by design.
One important source of difference between the two languages simply deals with timing of the releases of both Microsoft's IE and Netscape's Navigator. Netscape released its non-beta 3.0 version of Navigator slightly after the release of IE 3.0. With the final release of Navigator 3.0, Netscape introduced new features of the JavaScript language known as JavaScript version 1.1. Do not expect many of the features specific to JavaScript 1.1 to work in IE 3.0 or 3.01. Section 3.4 discusses the differences that stem from the introduction of JavaScript 1.1.