possible readline license problem with ghc and -package util

Ketil Z. Malde ketil@ii.uib.no
12 Jun 2002 11:03:35 +0200

Wolfgang Thaller <wolfgang.thaller@gmx.net> writes:

>>     1. Dual-license GHC under _both_ the current GHC license and
>>       the GPL

Not including the parts that aren't allowed, I suppose, i.e. Readline
the library, and the readline functionality of GHCi.  The library is
easy to avoid for developers, and GHCi is only a problem if you're
releasing a non-GPL Haskell interpreter based on it (i.e. it doesn't
have any effect for programs you write with it)

If somebody really requires a statically linked non-GPL Readline
replacement, they are free to write/adapt one, and submit it under

>>     3. Developer wins because lots of people like the GPL, and
>>        any development they do with the GPL is guaranteed to go
>>        back to the community.  This may not occur all the time if
>>        you only use a permissive license like the BSD license.

> I'm slightly afraid of this. What will prevent a code split between
> the GPL and BSD versions?

Well, it can happen, but I think it very rarely does in practice.

> (Developer loses because other developers will contribute patches only
> for the GPLed version. The GPL version will take all the code from the
> BSD version, but the BSD version will automatically stay behind.

So?  That's how the BSDL works -- it doesn't matter if the code is
re-released under GPL or a proprietary license, nobody is forced to
contribute any changes they make under BSDL.  Normally, they will,

But if you're worried about this, it is the BSD license that allows
it, not the GPL.

> 1) seperate the readline library from the utils package.

Is this really necessary?

> 2) put a warning on the readline package so that people who are not
> fluent in licenses won't accidentally use it for proprietary programs.
> 3) Make sure that the Windows version links with libgmp dynamically.
> 4) Leave GHCi as is.
> 5) If the FSF complains that GHCi should be released under GPL and
> that the current license is not "compatible enough", switch to a BSD
> lib. 

Sounds reasonable.

> IMHO, they won't complain in the first place.

Well, they could complain, but it'd be rather futile, since we'd be in
compliance with their license.

If I haven't seen further, it is by standing in the footprints of giants