Changes in license terms

John Cowan cowan at
Fri Aug 13 14:27:26 UTC 2010

Mahesh T. Pai scripsit:

> This is not legal advice; nor am I lawyer, 

Nor I.

> Michael Bradley said on Thu, Aug 12, 2010 at 05:28:09PM -0500,:
>  > from the MIT/expat license to LGPL v3, what are the principles of
>  > law, say in the USA, which prevent the new license terms from
>  > retroactively affecting earlier versions of his code released under
>  > different terms.
> I purchased a loaf of bread today. The price was USD 1.00. Me and my
> kids ate it yesterday night.
> Tomorrow, the baker increased the price to 1.25 USD. And asks me to
> pay 0.25 USD (I guess you call it cents). 

This case is not really comparable.  When you buy bread with cash, there
is a complete transfer of ownership: before you pay, the baker has all
the ownership rights; afterwards, you have all the ownership rights.
If the baker made a bad bargain, he has no one to blame but himself.

When you receive open-source software, you get a bundle of rights from
the copyright owner, but no transfer of ownership.  Since you have not
paid nor exercised any of those rights yet, there is no contract between
you (at least in common-law systems).  If the owner wishes to retract
those rights, he can do so; however, he would be required to provide
reasonable notice.

In addition, in U.S. law there is a special license-termination provision:
works copyrighted in the year N can have any or all licenses revoked
by the original author or his heirs any time between the years N+35
and N+40, and this right cannot be waived in advance, but reasonable
notice is required.  This is intended to help out authors who have made
bad bargains for works that turned out to be extraordinarily valuable.
No open-source works have come under this provision yet, as the GPLv2
only dates back to 1981.

If the license ripens into a contract, as when you exercise some of your
rights under the license (or is a contract in the first place because
you have explicitly assented to it), you might be able to get money in
various ways or even get limited rights ("equitable estoppel").  But in
practice a court, at least a common-law court, is very unlikely to tell
a licensor that he can't (with respect to future potential licensees)
change his mind.

Verbogeny is one of the pleasurettes    John Cowan <cowan at>
of a creatific thinkerizer.   
   --Peter da Silva

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