BSD and MIT license "compliance" with the MS-PL

Tzeng, Nigel H. Nigel.Tzeng at
Fri Apr 17 17:33:00 UTC 2009

>From: Matthew Flaschen [mailto:matthew.flaschen at] 
>No.  "You may distribute Covered Code in Executable form only if the
>requirements of Sections 3.1, 3.2, 3.3, 3.4 and 3.5 have been met for
>that Covered Code, and if You include a notice stating that the Source
>Code version of the Covered Code is available under the terms of this
>License, including a description of how and where You have fulfilled the
>obligations of Section 3.2."  Section 3.2 requires availability of
>source code.

3.2 requires source availability of modifications to source code.  1.9 
Defines what modifications are.

>Anyway, I only mentioned MPL as a side point.

It's not a side point if you assert that all copyleft licenses require
source distribution with all binary distributions and one does not.  

Then it's called "counterexample".

>In this instance, I disagree with license list.  The FSF defines
>copyleft as, "Copyleft is a general method for making a program or other
>work free, and requiring all modified and extended versions of the
>program to be free as well."

That is the definition for strong copyleft yes.  Weak copylefts obviously
do not require that all modified and extended versions must be "free" or
there wouldn't be a distinction between strong and weak.

>Clearly, if I release a Ms-PL program there is no guarantee all future
>derivatives will remain free.  One or more branches of the source code
>could be closed off forever.

This is true of all permissive licenses.  Perhaps the MS-PL license was not
accidently named and appropriately categorized as a permissive weak-copyleft 
open source license.

It is probably not in our interests to call any copyleft license "viral"
even if we don't particularly care for it.  There are already too many
nuances in open source licenses to voluntarily reopen that can of worms.

There probably aren't any neutral senses of that word used in conjunction 
with software licenses regardless of what disclaimers you attach.

More information about the License-discuss mailing list