Plan 9 license

Lewis Collard lewis at
Fri Nov 1 23:27:14 UTC 2002

John Cowan r sez:
> Lewis Collard scripsit:
> > The Plan 9 license forbids personal modification
> I agree, but so does the OSL 1.0, which is Open Source (the OSL 1.1
> does not have this problem).

Then I disagree with the certification of the OSL v1.0 as Open Source.
(No, I'm not trying to start a flamewar here.)

> How is this different from the following language from 2.1 of the P9L?
> # Distribution of Licensed Software to third parties pursuant to this
> # grant shall be subject to the same terms and conditions as set forth in
> # this Agreement, and may, at Your option, include a reasonable charge for
> # the cost of any media. You may also, at Your option, charge for any other
> # software, product or service that includes or incorporates the Original
> # Software as a part thereof.
> For comparison, clause 5 of the Artistic License says:
> <more snipping, I hate include wars>
> Looks like the same deal to me.

I concede the point on this matter, then (I didn't read the P9L close
enough, it seems). The wording in the P9L is even messier than that in
the Artistic license, IMHO (quite an achievement), but on this count at
least the P9L is no worse than the Artistic license.

(I was given to understand that the wording in the OSD, section 1, was
designed so as to not exclude Artistic-licensed software from being
Open Source, and that with the revised wording of the Artistic License
2.0, that it would be desirable to change the OSD to require any kind of
for-profit distribution rather than permitting licenses to only allow
aggregation with other products. Bruce Perens has said things along
these lines. Deviating a bit from the point of this thread, I know.)

Anyway, this discussion should be about whether the P9L qualifies as
open source, and as you pointed out the "termination-on-any-IP-lawsuit"
problem is clearly bad enough to disqualify the license alone.

On the subject of RMS's article, he considers the Artistic license
non-free too and in that he is consistent in dismissing the Plan9
license, which is far more restrictive. (I'd be interested to see his
comments on the OSL.)

Lewis Collard <lewis at>
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