Subject: Re: MS-PL/GPL compatibility, was Re: For Approval: Microsoft Permissive License
From: "Chris Travers" <chris.travers@gmail.com>
Date: Tue, 28 Aug 2007 11:15:57 -0700
Tue, 28 Aug 2007 11:15:57 -0700
Some have asked for an analysis of whether the MS-PL qualifies as a GPL v3
additional permission.  I have concluded that it is not because it cannot be
removed.  However, it may be possible to meet both licenses together using
section 7b legal/attribution notices.

The only analysis I have heard as to why the BSDL is compatible with the
GPL3 is that the BSDL only requires notice of the license, not the license
itself.  In this view, by changing the license, one essentially has no
effect on the software until it becomes encumbered by other copyrights.
Once this happens, it becomes effectively impossible to seprate the safe
components (including but not limited to code) from the unsafe ones without
access to the original BSDL code.

So, suppose we extend the BSDL to use section 7b legal/attribution notices
to identify portions which haven't been substantively altered.  Something
like:

* In addition to including this notice in the file, you must also identify
any sections of code that have not been substantively altered by placing a
comment at the beginning such as:  Begin Original Fragment <identifier>
copyright 2007 Chris Travers, who has granted a public license to this
portion under the notice listed in this file.  Fragment ends can be noted
with a comment such as: End original fragment <identifier>."

Although this only requires a notice be included, it has the effect of
identifying safe sections which can be extracted and distributed separately
under the terms of my modified BSD License.  In short, whatever other
copyrights encumber the file or work as a while, unaltered fragments are
still identified as safe for extraction.  GPL work authors are free to claim
what they want about relicensing, but they state they have no copyrights to
enforce on the marked fragments, so.....

The immediate question is:  Is such a license still compatible with the
GPL3?  It seems to be unless you consider that notice to be other than
reasonable.

So the next question is:  Is there a functional difference between this and
the incompatibility argument against the MS-PL?  Hence can one use such a
system to comply with both the MS-PL and the GPL3 simultaneously?

Best Wishes,
Chris Travers


Some have asked for an analysis of whether the MS-PL qualifies as a GPL v3 additional permission.  I have concluded that it is not because it cannot be removed.  However, it may be possible to meet both licenses together using section 7b legal/attribution notices.

The only analysis I have heard as to why the BSDL is compatible with the GPL3 is that the BSDL only requires notice of the license, not the license itself.  In this view, by changing the license, one essentially has no effect on the software until it becomes encumbered by other copyrights.  Once this happens, it becomes effectively impossible to seprate the safe components (including but not limited to code) from the unsafe ones without access to the original BSDL code.

So, suppose we extend the BSDL to use section 7b legal/attribution notices to identify portions which haven't been substantively altered.  Something like:

* In addition to including this notice in the file, you must also identify any sections of code that have not been substantively altered by placing a comment at the beginning such as:  Begin Original Fragment <identifier> copyright 2007 Chris Travers, who has granted a public license to this portion under the notice listed in this file.  Fragment ends can be noted with a comment such as: End original fragment <identifier>."

Although this only requires a notice be included, it has the effect of identifying safe sections which can be extracted and distributed separately under the terms of my modified BSD License.  In short, whatever other copyrights encumber the file or work as a while, unaltered fragments are still identified as safe for extraction.  GPL work authors are free to claim what they want about relicensing, but they state they have no copyrights to enforce on the marked fragments, so.....

The immediate question is:  Is such a license still compatible with the GPL3?  It seems to be unless you consider that notice to be other than reasonable.

So the next question is:  Is there a functional difference between this and the incompatibility argument against the MS-PL?  Hence can one use such a system to comply with both the MS-PL and the GPL3 simultaneously?

Best Wishes,
Chris Travers