Can you alter the MIT license?

[Ian Grigg]

> You can only license something you own the copyright on.

Precisely.  I'm not sure how you read that you can re-license
under different terms, this would be tantamount to public domain,
and the presence of a licence and copyright is evidence that
the MIT code at least is not in the public domain.

> > - The Free Software Foundation skirted the issue with its repackaging of the
> > X rendering capability into libxmi.  They licensed the new library under
> > GPL, but the original source files borrowed from X remain under MIT terms
> > (even though those files have most likely been modified to embed them in a
> > GPL library).
>
> It's the modification that's the key.  The FSF own the modifications, and
> the copyright on those is GPL.  MIT own the pre-modified code.  To the
> extent that the latter can be separated from the former, it can be
> distributed under MIT terms.  To the extent that they're inseparable, both
> licenses must be satisfied - possible, since they aren't contradictory.

The FSF did that?  So that means that you can mix GPL code
with other code and distribute both under the their respective
licences?  What effect does this have on that GPL distribution
clause?

This is a current sticking point for our software *.  We
have historically been BSD, but are thinking of expanding
that.  The question has narrowed down somewhat as to whether
we can include GPL, and the distribution incompatibility
has complicated acceptance.

Can anyone point to any FSF commentary on how that libxmi
code was released?  I'm assuming here that any re-licensing
of the MIT code wasn't possible as they don't own the code.
If I can show clear FSF precedent for mixed distribution
then acceptance of the GPL would be much easier.

iang

* cryptix.org.