[rayiner]

In the context of the parent comment: if you build a business cloning Microsoft's Win32 API, I don't think you can complain if you get sued in the same way you can for a patent troll.

And yes, I think Microsoft should get to decide whether it wants clones of Win32, and also that it's a waste of time for open source developers to implement non-open source APIs.

[pcwalton]

Taking that further, the following things would be illegal:

- The HTML parsing specification (created by reverse engineering IE6 without Microsoft's cooperation), and by extension all non-IE Web browsers.

- Except IE is also illegal, because JScript was a hostile clone of JavaScript, down to the APIs.

- The x86-64 ISA, for two reasons: first, because AMD cloned x86 to start with, and second because Intel cloned AMD's work after seeing its success.

- All versions of Unix in common use; thus, by extension, 95% of smartphones by market share.

- VMware, by providing implementations of the proprietary x86 supervisor instructions in user mode.

Reverse engineering of proprietary APIs for the purposes of interoperability has been responsible for a lot of technologies that we use all the time. I understand the argument about IP protection, but I think an absolutist position in the other direction is a bit too far. In all of the cases above, there is a specific reason why the dominant player responsible for the proprietary API was failing to capture a market need, and the legality of API cloning was what allowed a smaller player to come in, address that need, and achieve a better economic outcome. I'm having a lot of trouble imagining how a world in which all of the above things were illegal would be a better one--you could argue that the dominant player could have done each of those things, but the fact is that they didn't.

[rayiner]

It's not my position that you can copyright APIs per se. In my view, the protection in the Oracle case is a coincidence, stemming from the fact that you can't clone a Java API in Java without effectively copying the textual description of the API. So I don't think there would be a problem with reverse-engineering the operation of IE or x86 and describing it in an independently-written specification or implementing the same method of operation in another browser or CPU or in VMWare.

You're right about UNIX, but I don't think not being able to clone UNIX would've been any great loss to the world. iOS and Windows Phone would still exist, and I'm sure someone would have developed a cheap open source OS for the rest of the market.