I am recently reading about Node.js and got an interesting statement about JavaScript and Internet Explorer:

Internet Explorer doesn’t actually support JavaScript or ECMAScript; it supports a language variety called JScript. In recent years, JScript has fully supported the ECMAScript 3 standard and has some ECMAScript 5 support. However, JScript also implements proprietary extensions in the same way that Mozilla JavaScript does and has features that ECMAScript does not.

Source: .html#chap2_id35941400

Frankly speaking I am totally unable to understand the above statement. I know Microsoft has its own VBScript and it allowed JavaScript in IE that is why JS is more popular than any other scripting language. Is this statement true? If yes then the scripting engine of IE does the translations of native JavaScript to JScript or what is the other case?

I am recently reading about Node.js and got an interesting statement about JavaScript and Internet Explorer:

Internet Explorer doesn’t actually support JavaScript or ECMAScript; it supports a language variety called JScript. In recent years, JScript has fully supported the ECMAScript 3 standard and has some ECMAScript 5 support. However, JScript also implements proprietary extensions in the same way that Mozilla JavaScript does and has features that ECMAScript does not.

Source: http://chimera.labs.oreilly./books/1234000001808/ch01.html#chap2_id35941400

Frankly speaking I am totally unable to understand the above statement. I know Microsoft has its own VBScript and it allowed JavaScript in IE that is why JS is more popular than any other scripting language. Is this statement true? If yes then the scripting engine of IE does the translations of native JavaScript to JScript or what is the other case?

• javascript
• internet-explorer

Share Improve this question Follow edited Jun 20, 2020 at 9:12 CommunityBot 111 silver badge asked Mar 27, 2014 at 6:01 Awais QarniAwais Qarni 18k2525 gold badges8080 silver badges144144 bronze badges 3

• 3 JScript is basically JavaScript, the reason Microsoft had to use another name was trademark issues, not because it was any different. – adeneo Commented Mar 27, 2014 at 6:04
• 1 This is like how we have html standards, and each browser has its own interpretation of how to render html. Some features may be unsupported or beyond the specs, but it still ends up being a browser rendering html. – ps2goat Commented Mar 27, 2014 at 6:07
• 1 "Internet Explorer doesn’t actually support JavaScript or ECMAScript; it supports... Jscript. In recent years, JScript has fully supported the ECMAScript 3 standard" So they don't support ECMAScript, but they do fully support it. Alrighty then. – cookie monster Commented Mar 27, 2014 at 6:19

Add a ment  | 

3 Answers 3

Sorted by: Reset to default 2

ECMAScript is the official standard, JavaScript and JScript are implementations of that standard. Just like CPython and Jython are implementations of Python.

As so often if it's about browsers, they both don't necessarily fully support the standard or provide additional, non-standard features, partly because they started evolving when an official standard didn't exist yet.

From Wikipedia about JScript:

[Microsoft] did not want to deal with Sun about the trademark issue, and so they called their implementation JScript. A lot of people think that JScript and JavaScript are different but similar languages. That's not the case. They are just different names for the same language, and the reason the names are different was to get around trademark issues

From the Microsoft documentation about JScript:

JScript is the Microsoft implementation of the ECMA 262 language specification (ECMAScript Edition 3). With only a few minor exceptions (to maintain backwards patibility), JScript is a full implementation of the ECMA standard.

well, this mainly depends on the version of IE you are using, as you havent mentioned that no one can say that for sure

I think it is not like that instead Microsoft gives you an option to enable Javascript on your IE like this:

• Pull down your TOOLS menu
• Select Internet Options...
• Click the Security tab on the top of the resulting window
• Click the Custom Level button
• Scroll the list down to the entry for Active Scripting
• Check the Enable radio button.
• Click OK in all dialogs.

Also Jscript is same as Javascript

JScript is Microsoft's dialect of the ECMAScript standard[2] that is used in Microsoft's Internet Explorer.

JScript is implemented as a Active Scripting engine. This means that it can be "plugged in" to OLE Automation applications that support Active Scripting, such as Internet Explorer, Active Server Pages, and Windows Script Host.[3] It also means such applications can use multiple Active Scripting languages (e.g., JScript, VBScript, PerlScript, etc.).