License in the Mac installer

[Roman Leshchinskiy]

FWIW, here are my two kopeks.

Manuel M T Chakravarty wrote:
> * You can link a BSD3 program with a GPL'ed library and distribute the 
> result.  (This opinion is supported by the FSF listing BSD3 as a 
> GPL-compatible license on their web pages and this item in their 
> licensing FAQ: 
> <http://www.fsf.org/licensing/licenses/gpl-faq.html#LinkingWithGPL>.)

Two licenses are compatible (at least in FSF speak) if you can combine 
code distributed under the two licenses and distribute the result. That 
is, there must be a license under which the combined work can be 
distributed. In this particular case, that license is the GPL and that's 
the license under which your binary package ought to be distributed.

It would be possible to distribute GHC itself under BSD3 and readline 
under the GPL if they were really distributed as two independent thing 
(and, e.g., optionally linked together during installation). But by 
prelinking them, you have created a combined work which must be 
distributed under the GPL since it includes GPL'ed code.

> * That it is sufficient to include both BSD3 and GPL in the click 
> through license agreement of an installer, saying that GHC is under BSD3 
> and readline under GPL.  (What's the alternative?  To dual license GHC 
> in that agreement?  That's probably impossible as it AFAIK would require 
> a unanimous decision by *all* copyright holders of portions of GHC's 
> source code, which is quite a large number of people.)

The reason that the FSF considers BSD3 to be compatible with the GPL is 
precisely because you can take BSD3-licensed code and redistribute it 
under the GPL. The copyright holders have already given you permission 
to do that by using the BSD3 license - it places no constraints on how 
you license the code as long as you meet its conditions. Note that the 
original code is still available under BSD3; it's just that *you* chose 
to distribute it under the GPL.

At least that's the view of the FSF (IIUC). The OpenBSD guys think 
differently, for instance.

As to clicking through the license agreement, take a look at 
http://www.gnu.org/licenses/gpl-faq.html#ClickThrough
Basically, clicking through the license isn't necessary because it 
covers distribution, not use (in contrast to a EULA).

Roman