[DaiPlusPlus]

They're just extensions in the same way that GCC has its own extensions for C and C++.

J++ was created to counter shortcomings in the design of early Java language versions that Sun was not keen to re-integrate back into the Java language. That itself isn't bad (as other JVM-compatible languages exist, like Scala and Groovy) except that J++ then needed Microsoft's own Java VM with its own platform-specific runtime extensions - and that's what the Sun lawsuit was about. I agree it was badly handled by Microsoft, and in the end Microsoft just ditched Java and reinvented J++ as C# and the .NET Framework - which is where we are today.

As for JScript: before JavaScript was standardised there were extensions being added by everyone (Netscape had their own, as did Microsoft). I think Microsoft extended JScript in a very conservative way: the main change is the addition of the `new ActiveXObject` wrapper for COM objects which made AJAX possible, and also made JScript useful for automating Windows (and server-side JavaScript with ASP/JScript predates Node.js by 13 years!) - to my knowledge JScript itself didn't add any syntactical changes and provided you didn't use ActiveXObject your code would run without issue in other JavaScript engines. Note that this isn't the same thing as DOM extensions in Internet Explorer, of which there were many.

I think it's worth pointing out that when IE6 was released in 2001 it was by-far, the most W3C-compliant web-browser in existence: for CSS2.1, Netscape's then compliance level was abyssal, and even beating out Opera at the time too.