Initial Developer's Public License

Lawrence E. Rosen lrosen at
Wed Feb 11 21:29:40 UTC 2004

> >Can you indicate how your proposed license differs from the GPL, and 
> >how it differs from the Open Software License?
> Yes.  Unlike the GPL, the IDPL explicitly allows the software 
> to be distributed, linked, and included in commercial 
> software. Unlike the Open Software License, the IDPL requires that
>    if the source is modified, modifications must be published
>    under the IDPL license
>    and that if part or all of the code is included in another
>    product, interfaces between that product and the licensed
>    source must be published under the IDPL.


I'm not convinced that these requirements (as you've just described them)
are consistent with the OSD, nor have you accurately described the effect of
the Open Software License (OSL).

For one, the OSD allows private modifications. Modifications that are not
distributed need not be published. The OSL requires publication of modified
source code when the derivative work is distributed, but it does not
(cannot) require publication of private modifications.

Other software that is merely combined with open source software without
creating a derivative work cannot be affected by any open source license. So
there can be no requirement to disclose APIs or other interfaces of that
other software. Of course, if the original open source work is modified to
implement an API ***and that modified open source work is distributed***,
the OSL requires that the modified source code of the derivative work be
published, thereby disclosing at least one implementation of the API. 

/Larry Rosen

license-discuss archive is at

More information about the License-discuss mailing list