License compatibility of MS-PL and MS-CL (Was: (RE: Groklaw's OSI item (was: When will CPAL actually be _used_?))

Zac Bowling zac at
Sun Aug 26 17:56:59 UTC 2007

It really comes back to the basic issues with Microsoft's Shared
Source licensing program that people have been talking about for the
last few years. While they are legal licenses in a conventional sense,
they don't follow all the unwritten rules of open source licences that
we use in the F/OSS world.

For one, for the most part, our licenses are visioned and shared
source licenses are not yet. Second, our licenses have distinct names.
For a while Microsoft did not do any of that (everything was just a
"Shared Source license") and apps are still out there that simply have
the title "Shared Source" with entirely different licenses for each.
Just go take a look at Microsoft's CodePlex,
(Microsoft's version of SourceForge) at the IronRuby, IronPython,
Phanlanger, and other projects and all their variations of Shared

Microsoft recognized some of these issues with the new program to try
and start licensing under 3 different licenses (and the one variation
to each that restricts to Windows only). Still the license keeps a
good part of the confusing nature of the Shared Source licenses.

One of the best parts to many of our licenses is that they usually
have a preamble that explains the intent and purpose and goals.
Sometimes they even go into philosophy to some extent (GPL, MPL, etc).

What I'm afraid is that Microsoft would have a hard time writing up
their intent and putting it into the license clearly. They are not
used to it. No license except those in the F/OSS world do you see that
all that often.

What is odd is that in the F/OSS community, developers like you and
me, end up worrying about software licenses on our own without the
assistance of an attorney. Some of use doing this as our full time job
will take the time to look into it, but for the rest of us, we start
our projects out by ourselves, in our free time, and don't want to or
lack the money to not hire an attorney to figure it out. If we had to
get consulting from a lawyer everytime we wanted to start writing
code, it might kill most of the enthusiasm that makes our community

>From my experience, the developers in the F/OSS community are the
adventurous type. Many of us learned how to use the software and tools
that exist now by our self, we loved the software and and we got
involved in the community that made it happen, we learned out how to
program and contribute to projects in our world, and managed to do it
all on our own.

A good portion of the people I know in our community managed to get
started so without worrying about all the legal ramifications involved
because we could trust leaders of our community and follow what they
did to know what is ok. The OSI is one of those leaders in our
community for many of us and I know I can trust what the OSI approves
because of what is stated in the open source definition on the site
meets with my own goals.

The problem comes about when we get more into it and we become more
dedicated. We move on to new technologies and want to mix and match
software, or port software to run on another platform, or link to
other software to add functionality. That's when us as the developer
has to play lawyer, and try to do what we do best, and figure
everything out on our own. The only thing we have to go on is our
experience with the licenses we already use to help us out.

The problem is that we are not lawyers and we don't think like them.
You see a lot of lists, forums, and blogs with developers talking
about their own interpretations of a particular license. Things
usually get corrected pretty quickly as more people comment on the
subject of that license and a consensus of what is ok and what is not
ok to do with a license is finally met (sometimes the topic is about
using this license in conjunction with another license, like this
thread with GPL and Ms-PL mixing).

The problem with the Shared Source licenses is that its hard to
leverage our experience against it. This is horrible for us when
Microsoft creates a new Shared Source license for each product they
release. Then when the text is so similar to other variations we might
know we think it might be ok, but it turns out that the entire intent
is completely different of that variation, it causes issues.

Zac Bowling

On 8/26/07, Donovan Hawkins <hawkins at> wrote:
> On Sun, 26 Aug 2007, Zac Bowling wrote:
> > I get what you are saying about the different intents of Ms-CL and
> > Ms-PL. I was looking at Ms-PL as being lesser then the Ms-CL since
> > they have a lot of the same text where the Ms-CL only seems to add
> > more bullet points. If you look at it simply as they are only adding
> > to it, you don't think they are changing the entire intent of license.
> That's a good point...I had forgotten when people discussed the fact that
> there is only one place where the two licenses differ. It's reasonable
> that someone would expect more similarity in their intent.
> > What is confusing is that same line about "any portion of the
> > software" is used in other shared source licenses including the first
> > shared source license I can remember, the Rotor project (now the
> > Shared Source CLI). I've attached a copy of that version of the shared
> > source license for reference.  In that case that same exact section is
> > used but if what Jim said was true for the Ms-PL, the same exact
> > phrase means something entirely different for the other licenses.
> Actually the license you attached appears to be worded a bit differently,
> and "the software" still seems to apply to the unmodified version. In the
> section on modifications, they write "You may modify this Software and
> distribute the modified Software for non-commercial purposes, however, you
> may not grant rights to the Software or derivative works that are broader
> than those provided by this License." However I do agree that there is
> much to be said for defining your terms in advance and using them
> verbatim in the license body, rather than relying on English to
> disambiguate.
> Of course, the license you attached also says:
> "You may use any information in intangible form that you remember after
> accessing the Software.  However, this right does not grant you a
> license to any of Microsoft's copyrights or patents for anything you
> might create using such information."
> Uh, so I can use what I remember, unless I can't? Gee, thanks...
> ---------------------------------------------------------------------------
> Donovan Hawkins, PhD                 "The study of physics will always be
> Software Engineer                     safer than biology, for while the
> hawkins at                   hazards of physics drop off as 1/r^2,
>                biological ones grow exponentially."
> ---------------------------------------------------------------------------

Zac Bowling

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