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On Sat, 12 May 2007 12:41:58 +0100 |
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"Marcus D. Hanwell" <cryos@g.o> wrote: |
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> There is a template library called Eigen I would like to add to the |
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> tree. It is a dependency of an application I would like to add |
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> shortly. It will also end up being a dependency of KDE 4 (for |
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> kalzium). My question relates to the licence the code is released |
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> under. |
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> |
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> It is licenced under the GNU GPL, version 2 or later with the |
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> following exception, |
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This is a common situation with GPL compilers - some are licensed |
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so that they can be used to build non-GPL software, some can only be |
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used to build GPL software. |
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The situation with Eigen is similar to the "libgcc exception" for GCC. |
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We don't mention that in the LICENSE for gcc. This is the exception |
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that allows you to build non-GPL software with gcc (note for the |
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interested - if you build profiled executables with gcc, the GPL applies |
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to the built executable since the profile support code linked into the |
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executable is licensed purely under the GPL - not a real problem as |
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no-one distributes profiled executables!). |
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However there's also a similar exception for gnat-gcc; that has a |
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separate license file GMGPL which explains the situation there. |
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However this is talking about extra libgcc stuff that is |
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Ada-specific - the standard libgcc exception is not mentioned. |
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For information, gnat-gpl (the AdaCore-sponsored version) doesn't have |
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the exception, so is straight GPL - this also means you can't use |
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gnat-gpl to build and distribute BSD-licensed software, for example. |
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So currently we're inconsistent. We must be accurate in our license |
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declarations, I think, so my view is if Eigen has a license that is GPL |
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with some exception, that should be made clear. |
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All these exceptions are doing the same thing - relaxing the GPL as it |
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applies to the compiler (or template library in this case), so that it |
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does not apply to works created using it. I like the |
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"GPL-2-with-linking-exception" license name that the gnu-classpath |
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package uses; perhaps we could include (concatenate) all the exception |
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clauses that lead to the same thing into that license file and have the |
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relevant packages use that license name. |
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|
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-- |
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Kevin F. Quinn |
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