Changing the licensing terms for an application

[Rick Moen]

Quoting Hanxue Lee (feilongquan at myrealbox.com):

> I wish to know whether I can change the licensing term of an application
> from GNU GPL to BSD or vice versa.

The copyright owner(s) can affix whatever licence terms he wishes to
individual instances of the code.  _If_ you own a codebase's copyright,
and previously issued a copy bearing GPL terms, simply issue a second
copy bearing BSD terms.

> For example, the original progam is licensed using BSD license. I
> found out that some unscruplous developers are adding some new
> features and re-selling it without contributing back to the source
> tree. I wish to avoid this, so can I change the licensing terms from
> BSD to GPL?

Now, you have a more-complex situation, because presumably Mr.
Unscrupulous[1] Developer isn't assigning you copyright over his
additions.  You could ask him to do so.  If he does, then you own
the resulting revised codebase without being encumbered by third-party
rights.  If not, you can choose to either accept his additions under
whatever licence terms he specified, or leaving them out.  In the 
latter case, you continue to solely own copyright on your working copy.
In the former case, you and he would have to agree on any licensing
changes, as they affect property belonging to both of you.

> How about the other way round? If the licensing terms could be
> changed, is it only the original owner can change it?

Again, licensing is a grant of permissions by the copyright owner(s)
affecting an _instance_ of the codebase.  Most such grants are written
so as to be basically irrevocable -- as to that code instance.  Being
the copyright owner, he can however issue other instances with any
desired differing terms.

[1] I will ask, before our honoured friends in the BSD community beat me
to it:  _Why_ would you call this unscrupulous behaviour?  That's not 
reasonable.  Your placing the original work under the BSD licence
specifically authorises any third party to create proprietary forks.  If
this possibility surprises you, you should study licensing much more
carefully before leaping in without understanding the consequences of
licensing decisions.

-- 
Cheers,                        My pid is Inigo Montoya.  You kill -9    
Rick Moen                      my parent process.  Prepare to vi.
rick at linuxmafia.com
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