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Python's CRT licensing on Windows


On Windows, the standard Python 2.4 distro is compiled with Microsoft
Visual C++ 2003 and is shipped with msvcr71.dll as a part of the binary
installer. That is ok, as those who has a license for Microsoft Visual
C++ 2003 is allowed to redistribute msvcr71.dll. Without a license for
Microsoft Visual C++ 2003 one it not allowed to redistribute this DLL.

This has some interesting implications:

** If you don't have Microsoft Visual C++ 2003, is it illegal to
redistribute the binary Python installer from www.python.org? Does
redistribution of Python also violate Microsoft's copyright on the CRT?
And if so, is someone developing in Python required to ask the customer
to download a binary installer from www.python.org (instead of shipping
a copy)?

** Not everyone that develops in Python has a license for Microsoft
Visual C++ 2003. I have the Microsoft Visual C++ 2003 Toolkit, but it
only allows me to link and redistribute a static version of msvcr71.
So, does this prevent me from using Py2Exe?

** It is apparently not possible to buy a license for VS2003 anymore,
as the product has expired. One can only buy a new get a license for
VS2005, which allows redistribution of msvcr81.dll, but not
msvcr71.dll. Microsoft said something about a right to "downgrade the
compiler" once a license for VS2005 is bought, but I am not sure if
this applies to the crt redistribution rights as well.

I understand that Microsoft has donated Microsoft Visual C++ 2003
compilers to key Python developers. That is generous of them. But what
did they say about the crt licensing?

Oct 25 '06 #1
7 2615
sturlamolden wrote:
On Windows, the standard Python 2.4 distro is compiled with Microsoft
Visual C++ 2003 and is shipped with msvcr71.dll as a part of the binary
installer. That is ok, as those who has a license for Microsoft Visual
C++ 2003 is allowed to redistribute msvcr71.dll. Without a license for
Microsoft Visual C++ 2003 one it not allowed to redistribute this DLL.
that's a myth, based on a flawed reading of the MS license. to repeat
myself from various other fora:

"As long as you're using a standard Python build, you don't need to
buy VC7 to [legally redistribute the C runtime]. The python.org team
use a properly licensed VC7 to build Python, which turns Python into
"licensee software" and you into a "distributor" doing "further
distribution" of Python to end users (with your own stuff added on
top, of course). And further distribution is perfectly okay, as long
as you only ship the MS components together with proper "licensee
software" (=Python), and that all parties respect the relevant
portions of the original EULA (this basically means that you cannot
use tricks to circumvent the MS EULA, e.g. by attempting to relicense
the MS DLL's under less restrictive licenses or "viral" licenses. The
same applies to all other licensed components, of course. You cannot
relicense the Python core either.)."

"(If in doubt, consult a real lawyer. If you do, make sure that he/she
understands the various levels here -- i.e. that "you" in the MS
EULA applies to the Python developers, not yourself)."

</F>

Oct 25 '06 #2

Fredrik Lundh wrote:

I am not intentionally posting FUD.
"As long as you're using a standard Python build, you don't need to
buy VC7 to [legally redistribute the C runtime]. The python.org team
use a properly licensed VC7 to build Python, which turns Python into
"licensee software" and you into a "distributor" doing "further
distribution" of Python to end users (with your own stuff added on
top, of course).
That makes sence. One does not need a VC7 license to sell (aka
"distribute") software from a store either.
And further distribution is perfectly okay, as long
as you only ship the MS components together with proper "licensee
software" (=Python), and that all parties respect the relevant
portions of the original EULA
Is further "distribution" okay if it is only accompanied by the python
runtime DLL (as is the case when using Py2Exe) or should the entire
python-2.4.4.msi from python.org be "distributed"?
"(If in doubt, consult a real lawyer. If you do, make sure that he/she
understands the various levels here -- i.e. that "you" in the MS
EULA applies to the Python developers, not yourself)."
I certainly don't understand the EULA, and thus I cannot make sure that
I lawyer understands it either. But I can certainly find a lawyer that
charges $$$$ an hour and pretends to understand it. I am sure buying a
copy of VC7 is a lot cheaper.

Oct 25 '06 #3
sturlamolden wrote:
I certainly don't understand the EULA, and thus I cannot make sure that
I lawyer understands it either. But I can certainly find a lawyer that
charges $$$$ an hour and pretends to understand it. I am sure buying a
copy of VC7 is a lot cheaper.
When you buy that copy of VC7, buy me one too. By your logic, it will
_still_ be cheaper than $$$$ for a lawyer, so you win!

Thanks in advance!

Oct 25 '06 #4
sturlamolden schrieb:
Is further "distribution" okay if it is only accompanied by the python
runtime DLL (as is the case when using Py2Exe) or should the entire
python-2.4.4.msi from python.org be "distributed"?
As Fredrik Lundh says: Ask your lawyer. We cannot really interpret the
Microsoft license for you (I can only give it to you in case you don't
have it), and I can't formally give you permission to do copy something
that Microsoft has the copyright to.

If you are asking whether python24.dll should be treated as "Licensee
Software": then yes, I believe it is "Licensee Software".
I certainly don't understand the EULA, and thus I cannot make sure that
I lawyer understands it either. But I can certainly find a lawyer that
charges $$$$ an hour and pretends to understand it. I am sure buying a
copy of VC7 is a lot cheaper.
So what do you hope to get from the newsgroup article? Free legal
advice? You can't really get that; you can only get opinions. You
still have to draw your own conclusions.

Regards,
Martin
Oct 25 '06 #5

Martin v. Lwis wrote:
As Fredrik Lundh says: Ask your lawyer. We cannot really interpret the
Microsoft license for you (I can only give it to you in case you don't
have it), and I can't formally give you permission to do copy something
that Microsoft has the copyright to.
I wasn't asking you to.
So what do you hope to get from the newsgroup article?
Maybe someone have gone through the trouble and got a clear answer from
Microsoft.
Free legal
advice? You can't really get that; you can only get opinions. You
still have to draw your own conclusions.
You only get "opinions" from lawyers as well. I am not really
interested in anyone's opinion, lawyer or not.

Oct 25 '06 #6
sturlamolden wrote:
Maybe someone have gone through the trouble and got a clear answer from
Microsoft.
As far as companies go the EULA is as clear of an answer as you can
possibly hope for.

As for the original post, don't bother with it this issue, the chances
that MS will start harassing you for including this DLL is just about
zero. You could just as well worry that someone patented the right
click or the scroll bar.

i.

Oct 25 '06 #7
To paraphrase an applicant for a job vacancy we're currently filling when
asked to give an example of their problem solving skills:

A client had a problem with Windows XP on his laptop. I reformatted his hard
disk and installed Red Hat. Problem solved.

--
Dale Strickland-Clark
Riverhall Systems - www.riverhall.co.uk

Oct 25 '06 #8

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