Partial OpenSource products/licenses?

James E. Harrell, Jr. jharrell at
Wed Oct 2 17:55:05 UTC 2002

Open Source friends,

Many, many thanks to all you. As always, it is a pleasure to get
the feedback and opinions of the experts on your public list. I am
confident we'll be publishing a cool open source product in the
near future!

With Regards,

>-----Original Message-----
>From: Mitchell Baker [mailto:mitchell at]
>Sent: Wednesday, October 02, 2002 1:54 PM
>To: lewis at
>Cc: license-discuss at
>Subject: Re: Partial OpenSource products/licenses?
>I believe the difference is that the MPL does not require two versions
>of the same code, one open and one closed.
>Our system is to allow one version of the open tree, to which everyone
>would contribute.  Copernicus would also keep a second tree, containing
>the closed source material.
>Copernicus would participate with everyone in the open source project.
> When Copernicus builds its commercial product, it would pull form the
>open source project, then add in closed source additions to build its
>commercial product.  Returning to the Netscape example, this is what
>Netscape does.  Netscape engineers participate in the source
>tree, and get the critical benefits of the open source project.
>Netscape pulls from that open source tree, then pulls from a separate
>closed source commercial tree to complete its product.  This means
>anyone can pull the same thing from mozilla as Netscape does.  (Any many
>do, forming the variety of Mozilla distributions.)   But no one else can
>pull from Netscape's commercial tree, because that remains proprietary
>to Netscape.
>I use Netscape as an example because it is so well known, but numerous
>other companies do the same thing as well.
>Lewis Collard wrote:
>>John Cowan:
>>>That way lies great pain and suffering for everyone.
>>>Instead, I recommend you use the Mozilla Public License, and
>have two versions
>>>of your product.  "ProductX Open" is fully open source under the
>MPL, which
>>>basically allows people to create closed-source derivatives as
>long as they
>>>reveal actual patches to the source (as opposed to additions).  "ProductX
>>>Gold" is a derivative of ProductX Open, but is closed-source.  By using
>>>the Netscape modification to the MPL (see the NPL), you can have patches
>>>submitted to ProductX Open made reusable in ProductX Gold as well.
>>Couldn't you use the GPL too for this purpose? If you are the copyright
>>holder for the entire code is there anything stopping you from releasing
>>modified versions under different licenses?
>>	-- Lewis
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