How exactly did Microsoft reverse engineer Brendan Eich's JavaScript, call it something else and not get a massive lawsuit in the aftermath? I understand this was a long time ago but I still wonder how such a blatant rip-off did not result in massive litigation?

  • 1
    To laze to write my own answer again: stackoverflow.com/questions/135203/… – UncleBod Mar 24 at 14:48
  • @UncleBod except that JScript was released before ECMAScript was a thing. (Although presumably Netscape knew, when JScript was released, that they would be pushing ECMAScript, so suing wouldn’t have made much sense.) – Stephen Kitt Mar 24 at 15:32
  • 2
    Nevertheless, Javascript is an outward-facing language hacked together in a week so Netscape presumably fully documented it from the start? That'd undercut the suggestion that any reverse engineering was involved. – Tommy Mar 24 at 15:34

How come there are C compilers not written by Bell Labs? ;-)

As far as I am aware, there is no prohibition on producing your own implementation of a programming language based on the description of that programming language.

You can't copy someone else's implementation without their permission.

You don't need to reverse-engineer an implementation if there is a description of what the language constructs are intended to do; and with a programming language there almost always is such a description (otherwise there's not much point to it).

| improve this answer | |
  • 4
    The jury's still out on that; Oracle's attempt to sue Google over Google's reimplementation of parts of Java and whether the API symbols, etc, can be considered copyrightable material, was due to return again to the US Supreme Court last week before COVID-19 threw a spanner in the calendar. – Tommy Mar 25 at 1:30
  • 1
    Ha, I thought that was settled. I see not. Thanks. I don't think that case changes the broad outline of my answer yet, – another-dave Mar 25 at 1:53

Javascript became a standard known as EMCA Script, and Microsoft's implementation of it was JScript.

| improve this answer | |
  • 1
    It looks like JScript predates ECMAscript by 15 months though? That said, it was also Netscape who were keen to create a standard as quickly as possible, so I really don't think even Netscape would think that Microsoft had done anything dishonest in attempting to implement the same standard even before its formalisation. – Tommy Mar 24 at 17:41
  • 3
    @user, JScript was released before JavaScript became ECMAScript (or at least, before ECMAScript was published). – Stephen Kitt Mar 24 at 17:41
  • Before it was ratified as a standard. It's common for implementations to precede the standard. – user Mar 25 at 21:51
  • But you’re saying that JScript is Microsoft’s implementation of the standard; if that’s true, it can’t have preceded the standard. – Stephen Kitt Apr 16 at 12:24

Not the answer you're looking for? Browse other questions tagged or ask your own question.