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Linux in a product

Discussion in 'Electronic Design' started by Michael, Oct 30, 2005.

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  1. Michael

    Michael Guest

    This may not be the exact group to post this to but I'm more likely to get
    the right answer here.

    Let's say I had a product idea that involved a simple motherboard and an
    operating system.

    I had thought that Linux was the way to go but seeing that many of the
    distributions are for "non commercial" use only.

    What possible ditributions of Linux should I look at for inexpensive fees or
    preferably no restriction use?

    This is a simple idea and want an operating system that would be easy to
    learn (and not overkill).
  2. Ian Bell

    Ian Bell Guest

    There is no reason why you cannot build linux into a commercial product -
    there are tens of thousands of set top boxes out there that do just that.
    What you have to be careful about is modifications to source code of any
    software in it.

  3. Zak

    Zak Guest

    In short: you must make teh source code of your product available of
    parts you took from 'linux' - thus also the modifications.

    As for non-commercial use: these will not be based on copyright of code
    under the GPL license.

    The vendor may have bundled other code with a different license, or, as
    I understand it, use a logo and other trademarked items (such as their

    Using Linux can be free, but it still is copyrighted software: you need
    to understand the license to see how to do things and what your
    obligations are. And some things are not allowed.

  4. Guest

    No such thing really. Even the most expensive embedded linux solution
    have to abide by GPL restrictions. But most of us who have done this
    find GPL restrictions quite easy to live with.

    Basically, if you modify linux, you must share your modifications. So
    most of us don't modify linux. We just run our custom apps on top of
    it. The linux source must still be distributed with the product. But
    simply posting the source on a web page is enough to comply with GPL

    As for your own custom app, there are no such restrictions. You own the
    copyright to your own code so do with it as you please.

    So, regardless how much you pay for your linux, you must still comply
    with GPL rules. But as I said, nothing to be worried about.

    There is a separate issue with libraries that often gets confused with
    this. If you use GPL libraries in your code, then you must make your
    code GPL as well and give away your source. This has nothing to do with
    Linux. If you use the libraries to develop Windows applications you
    will still be bound by the license of the libraries. An example of this
    is the early version of GNU SASL library.

    If you don't want to share your code, don't use GPL libraries. LGPL is
    ok since it is less restrictive. BSD based licenses are better.

    At the company I work for all our libraries are in-house. We always
    re-invent the wheel just to make sure everything is legal.
  5. Guest

    GPL - Yes, you have to make your app GPL as well. This is the famous
    'viral' nature of GPL.

    LGPL - No, your app don't have to be GPL. Only modifications to the
    library needs to be.

    BSD - Do whatever you want.

    The nature of GPL actually makes it impossible to write GPL plugins to
    non GPL programs like Photoshop since it implies that Adobe needs to
    make Photoshop GPL as well even if it's the end user who loads the
    plugin. For this situation the LGPL (Lesser/Library GPL) was created.
  6. Buddy Smith

    Buddy Smith Guest

    Only if your app uses GPLd code. An embedded device can have GPLd
    applications on it. And, you can write a non-GPL program that exec()s a
    GPLd program. Now your program does NOT have to be GPL'd.
    No, the BSD license does have conditions of it's own. Namely, you have
    to place a notice of some sort in the product documentation. "Public
    domain" mans do whatever you want (see
    This is not correct. I can't write a GPL module for a non-GPL program
    and use that to force the original developer's code into GPL. Just like
    I can't sell your car to someone else without your permission.

    It'd be perfectly fine to write a GPL'd plugin for a commercial
    application, and it would not force the other developer to relicense
    _their_ product. Don't be silly.

    On the other hand, it would be strange to release a module as GPL...LGPL
    is more appropriate.


  7. Joel Kolstad

    Joel Kolstad Guest

    I think the OP meant that _Adobe_ would have a hard time writing GPL modules
    for Photoshop without someone claiming that they then had to release the
    source code for Photoshop. Is that not the case?
    There are people out there who actively try to dissuade people from using the
    LGPL. I really believe that some of them would rather that software not be
    written at all (even if it's given away freely) than to not have access to the
    source code.

    There a pretty silly (IMO) thread over on about how the death of the
    author of some popular (freely distributed) software package has somehow
    harmed its users due to the guy's estate not being willing to hand over its
    source code (rumor has it they actually shredded his CDs and printouts!).
    Seems they're kinda looking a gift horse in the mouth there... Unlike the
    ideal world where the author would have GPL'd the software and "the community
    at large" would continue development, I think the real world runs more along
    the lines of (1) the author might have never written the program if it had to
    be GPL'd in the first place and (2) even if it had been, there's probably less
    than a 1% chance that anyone else would have continued its development.

    The people I admire most are the ones who are pro-free software (and other
    forms of intellectual property) but not simultaneously anti-commercial

    ---Joel Kolstad
  8. Ian Bell

    Ian Bell Guest


  9. Buddy Smith

    Buddy Smith Guest

    If Adobe wanted to, they could release plugins with a dual license: Use
    this with photoshop, or use the GPL. At that point, anyone else who
    wanted to load those plugins in their applications would have to make
    their applications GPL'd. So in that case, it would make sense.

    There's a lot of dual licensing that goes on, especially when the GPL
    gets involved.


  10. Guest

    Read the question I answered.

    You can obviously write GPL plugins for non GPL programs physically.
    Nobody's there to physically stop you. But it makes the legality of
    using the plugin very complex. Lets analyse this a bit.

    GPL states that any code which links to GPL'd code must be made GPL as
    You write a Photoshop plugin and GPL it.
    Therefore, the end user must agree to your license (GPL) in order to
    use your software unless you say otherwise.
    This means, to comply with your conditions to use your plugin,
    Photoshop must be GPL. It obviously is not so your plugin immediately
    invalidates its own license.
    But wait, GPL makes exceptions on code not meant for distribution. So
    you can use the combination - Photoshop + GPL plugin as long as they
    are not distributed together.
    But GPL also has strict definitions of what distribution means. And you
    have to make sure you adhere to those.

    My point is, yes it can be done if you want, but why release code with
    such confusing and conflicting licensing when you really should be
    using LGPL?
  11. Ian Bell

    Ian Bell Guest

    Wrong, because your code links to Photoshop not the other way round.

  12. Guest

    If the violator had widely distributed GPL code without a valid
    license, the choice might come down to a huge copyright infringement
    judgement, or a settlement built around opening the source to achieve
    licensing compliance.

    If they refused to settle and the infringement judgement exceeded the
    value of infringer's other assets, it's possible the plantiff might be
    awarded ownership of whatever copyrights the infringer did have, if
    such a plantiff were a GPL-promoter they would probably take it and
    re-release the product in full compliance with the GPL. Unless the
    product has enough unique new value to justify removing and replacing
    the GPL code, it's unlikely that selling it to a third party would
    raise the necessary cash to settle the judgement.
  13. Guest

    Read GPL. By definitions in GPL Photoshop links to your code since it
    is the one 'loading' the plugin.
  14. Guest

    It can't be quite that simple.

    Say I have a GPL application running on a machine with a proprietary
    OS, windowing system, and window manager. If I launch the GPL
    application by selecting it from a window manager menu and it is then
    loaded and executed, how is this fundamentally different from a plugin
    for a special purpose "image processing operating system" like

    There has to be a dividing line somewhere... published API's or
    something. But couldn't a plugin interface be published? It seems to
    get down to a semantic argument over what is operation system vs
    application, compared to what is application vs plugin...
  15. Joel Kolstad

    Joel Kolstad Guest

    Having to define this dividing line is one of the reasons many companies are
    leery of using GPLd software!

    One easy to define dividing line would be whether or not the code of the GPLd
    software runs in the same process space as that of the caller -- this way it's
    OK for a proprietary Windows manager to invoke the GPLd code, and for
    something like Photoshop you could cleanly setup up something like a mail slot
    RPC interface between the two, although any form of 'direct call' interface
    wouldn't cut it.

    Photoshop most likely uses a COM interface to its plug-ins... anyone know for
    sure? Depending on how the threading model of the COM component is set-up,
    though, the plug-in may run in or out of process which makes this all kinda
  16. Ian Bell

    Ian Bell Guest

    Wrong again. This is exactly the same as Open Office reading a text file and
    there is no requirement to make your text file open source.

  17. Guest

    Ian, have you read through the GPL license? A document is not
    'executing code'. GPL only covers executable code. The definition of
    'linking' loosely tranlated is calling a function in a library/file.
    Parsing a file is not covered. That's why it's OK to develop non-GPL
    scripts that runs on GPL'd intrepreters.

    Also, GPL allows using non-GPL plugin/library/dll in GPL'd code, not
    the other way around. So your example should be reading a GPL'd
    document in Microsoft Word.

    But as Joel Kolstad replied earlier, even this is already dealt with by
    the GPL license. It's allowed to use a GPL *code* (not just a document
    or script) with a non-GPL application as long as they both don't run in
    the same process space. For example it's OK to use a GPL database with
    your code as long as they communicate via pipes, TCP etc.

    These are not my definitions but GPL's.

    Again, my point is if you want to develop a dll/plugin for a commercial
    application you should be using LGPL.
  18. Ian Bell

    Ian Bell Guest

    Do you understand the difference between loading and linking?

  19. Guest

    How would you classify dynamic linking?

    Or going the other way, what about registering a callback function to
    respond to events from the host application, window manager, or OS ?
  20. Guest

    As an engineer, yes. A plugin is not simply loaded in the same manner
    as a document. A document is simply parsed - no subroutine call is made
    into code in the document. By subroutine call the GPL recognises only
    machine language calling, not interpreting scripts. Simple loading of
    an image into does not 'link' into that image. However, when the image
    them gets 'executed' by the CPU, it must be done somehow by a
    subroutine call even if it is indirectly by function pointers. The GPL
    classifies this as linking, in this case dynamic linking. A plugin is
    simply a library/dll that the programs first checks if it exists before
    linking. Unlike hardcoded libraries the program still works even if the
    plugin doesn't exist. The program doesn't even need to know in advance
    the names of the plugin since it knows where all plugins are located
    and simply scan through the directory.

    This situation is just a bit more complicated if we are talking about
    intrepreted languages. But that's another story..

    Note that if you read GPL carefully there is a workaround for people
    like me who still want to use GPL'd code in a commercial product
    without making my own code GPL. Simply write another simple wrapper
    application which acts as a 'server' of the GPL functions. This simple
    application can harmlessly be GPL'd since it doesn't contain any
    business logic. Then connect the two via external means: pipes, TCP/IP,
    RPC, mailboxes, etc.. On a good operating system with very fast
    messaging such as QNX, this is almost as good as calling the function
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