[copyleft-next] Compatibility with Eclipse Public License.

Luis Villa luis at tieguy.org
Tue Aug 7 05:34:54 UTC 2012

On Mon, Aug 6, 2012 at 5:07 PM, Tom Marble <tmarble at info9.net> wrote:

> AFAICT the incompatibility rises from the EPL choice of venue [2]
> which makes EPL not GPL compatible.

Hi, Tom-
There is a deeper problem, inherent to the nature of copyleft. EPL states:

"When the Program is made available in source code form:

a) it must be made available under this Agreement;"

That's the essence of the copyleft, and says "once the source is under
this license, it must stay under this license." Other copylefts have
the same kind of language, leading to a conflict - both licenses say
"the _entire copylefted work_ must be under this license," so as soon
as there is overlap between the two copylefted works (say, because you
place one EPL file in a GPL application, or vice-versa), you have a

MPL 2, Sec. 3.3, or copyleft.next Sec. 11, get around this to some
extent, but only one-way. Short of an EPL 2.0 that has a similar
clause I don't think you can have the sort of compatibility you seem
to envision.


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