Swift is open-source but is it patent-free as well?

ebup · January 13, 2019, 8:50pm

So it seems that some or all of Swift is open-source, I'm not sure what if any parts of it are not at this point.
But I am now wondering, are there any Apple patents that people need to take into account or worry about when adopting Swift?

SDGGiesbrecht · January 13, 2019, 8:56pm

github.com

apple/swift/blob/main/LICENSE.txt

                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

    TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

    1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the

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ahti · January 13, 2019, 9:08pm

I'm no lawyer so take all this with a grain of salt, but the relevant part of the license seems to be this: swift/LICENSE.txt at ecebce8b2eae7613dd8422fb8bcd7e519d0606cd · apple/swift · GitHub

So as I understand it you'd only have to worry if someone contributed some patented construct to Swift without having a right to do that (and even then I don't know whether it'd be users of Swift or the contributor that would be in trouble). I know this sometimes becomes relevant in video codecs, but I don't think you'll need to worry much about this with Swift.

ebup · January 14, 2019, 6:16pm

I think you folks are misunderstanding me. I'm not interested in whether Apple is going to take my patents. I'm interested in the moral issue of whether Apple has patented parts of Swift itself. There is a plague of software patents nowadays, for instance US 9,672,152, in which every tiny detail of how software works is getting patented even though there is ample preexisting use of those same mechanisms i.e. Prior Art. If Apple has patented parts of Swift, then at any time they can demand payment for anyone using the patented parts of the language or runtime, and you may find the friendly face disappears and is replaced by the angry monster demanding a pound of flesh.

nuclearace · January 14, 2019, 6:35pm

In what context are you talking about? Are you thinking about lifting pieces of code of the Swift compiler into your own work? Because with that, I think you might run into issues with the license and any patents used in the software.

Or are you talking about using Swift on your server/app/IoT device? Because if they could do this, and did, I could almost guarantee a tremendous backlash that would almost certainly cause Swift adoption to drop to next to nothing. So I wouldn't worry too much about it.

John_McCall · January 14, 2019, 8:06pm

Swift is licensed under the Apache license, which includes a clause stating that all contributors, implicitly in the act of contributing, grant a license to all users to use any component of any patent they own that is necessary in order to use their contributions as part of Swift. That grant is perpetual and irrevocable with regard to both all past contributions and all current contributions. Apple could, in theory, publicly declare at any point that its future contributions will no longer be licensed under the Apache license, and then it could pursue patent infringement claims against any users of versions of the Swift code that incorporate those future contributions. However, (1) that would obviously kill the project, so (2) we have no intention of doing that, and (3) you would know about it in advance if we did because we'd have to be very explicit about it, and finally (4) you'd still be able to freely use all versions of Swift up to that point.

Nevin · January 15, 2019, 1:54am

This leaves unspecified what happens when a contributor violates the license by contributing code which they themself do not legally have the right to.

It is even conceivable that someone might have the legal right to a piece of code in one jurisdiction but not another.

John_McCall · January 15, 2019, 2:13am

Yes, but that’s not what we were talking about.

I’m not sure that there’s anything we could do about that particular risk — someone contributing code that they do not in fact have copyright or patent rights to contribute — as a project, other than responding promptly to any notice of violation. At any rate, it’s not an Apple- or Swift-specific problem. I’m fairly certain this cannot possibly affect you if you’re just using a project- or Apple-supplied toolchain, but if you’re very concerned about this, you should talk to a patent attorney.

Chris_Lattner3 · January 15, 2019, 6:35am

I am not a lawyer, and this is not legal advice.

However I can share that the choice of releasing Swift under the Apache 2 license was specifically driven by the goal of allowing widespread adoption and use of the code, without worrying about patents or other related issues.

I don't speak for Apple at all, but my understanding is that they want to see the code used very widely.

-Chris