Partial OpenSource products/licenses?

Mitchell Baker mitchell at
Wed Oct 2 17:16:07 UTC 2002

(esending, bounced the first time)

The Mozilla Public License ( 
was written in large part to allow this sort of combination. In the MPL
world, individual files governed by the MPL must always be open source. A
vendor is free to combine those files with other files, which may be proprietary,
or governed by another open source license. The combined executable may
be shipped under a license of the vendor's choice, provided that the recipient
is told where an how to get the MPL files.

Many companies do exactly this. For example, Netscape takes MPL code, combines
it with proprietary code (such as a Java Virtual Machine, AOL Instant Messanger),
and ships the combined result under a Netscape end user license agreement
for its Netscape 7 browser suite.

The limitation of the scope of the MPL to particular files rather than an
entire application can be found in Section 1.9 (definition of a Modification,
which must remain open source) and Section 3 (oblications regarding Modifications).
Section 3.7 explicitly states that you may combine MPL with other code not
govened by the MPL.

Hope this helps,
Mitchell Baker

James E. Harrell, Jr. wrote:

>Open Source friends,
>Pardon if you find this off-topic. I tried to retrieve the FAQ from the
>list, but it doesn't exist, and can't seem to find a list charter. Can't
>find a good list search either. Anyway, I've read many of the licenses and
>some of the posts, but I don't see a good way to do what we're interested
>My question to this group pertians to bridging the gap for commercial
>applications and the world of Open Source. Quite simply, is there a license
>(or would this group ever consider a license) that allows for a "Partial
>Source" product- perhaps a 95% Open Source license?
>Here's a little reasoning, comments flames and criticisms are welcome, while
>constructive discussion is encouraged:
>We have a product that we are considering publishing as open source. The
>would be available for free download and use. Some features would be limited
>though, and only available if you purchase a commercial license. Thus, a
>of the code (containing a license key manager) would necessarily be
>in order to prevent someone from easily removing the license checking.
>We enjoy many of the benefits of open source software, and would like to
>back. The major base of our software has some good stuff in it- that we're
>more than
>happy to publish and allowing anyone else to use/copy/redistribute, etc.
>We would like to do so in a way that allows us to still produce commercial
>products that are (paritally) closed source. After all, we have a payroll to
>cover. ;)
>Of the major companies that appear to be making money on open source
>products, it
>appears the primary method of doing so is via related services. However,
>do not scale as well (commercially) as do products.
>So I'm searching for the happy medium. Thoughts?
>James Harrell, CEO
>Copernicus Business Systems, LLC
>license-discuss archive is at

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