Replacement for GMP: Update

[Peter Tanski]

Florian:

> On most systems, readline is GPLed.  There is a non-copyleft
> reimplementation somewhere, but I don't think it's widely used.

The non-copyleft implementation is an upgrade from BSD's lineedit,  
called libedit <http://www.thrysoee.dk/editline/>.  Apple's OS X  
includes it as a version of libreadline by a adding "/usr/lib/ 
libreadline.dylib" as a symbolic link to libedit.dylib.  (I had  
forgotten about this because I have a version of Darwin Ports's  
libreadline I had installed so I could build GHC on OS 10.4: libedit  
does not fully implement libreadline's API so GHC requires libreadline).

That GHC includes libreadline is not a problem for developers  
compiling programs using GHC because libreadline is used for GHC's  
interactive bytecode interpreter, GHCi, which is part of the compiler  
system but is not linked into the RTS of compiled programs.  (This  
might be a problem with GHC's BSD license; I don't know.)  Clearly  
the best solution would be to write to the FSF.  The whole purpose of  
licensing GHC as BSD3 is to promote the broad use of Haskell as a  
programming language and developer involvement in the support,  
maintenance and research of Haskell and the GHC compiler.  Those  
goals realistically require commercial developer support, otherwise  
small company or individual developers who lack the market  
recognition to sell software as a service could not write  
applications in Haskell and compile them with GHC.  There are a few  
companies that do profitably sell Haskell as a service, notably  
Galois Connections, Aetion Technologies, Bluespec, Erlang Training  
and Consulting and OM Consulting.

>>  the "no further restriction" clause is
>> so broad
>
> It has to be very broad, otherwise developers could bypass the
> copyleft concept.

True.

>> the same clause (verbatim) in section 10 of the LGPL means the GPL
>> license is incompatible with the terms of the LGPL!
>
> The LGPL permits relicensing of covered works under the GPL.  Without
> that provision, it would indeed be incompatible with the GPL.

Are you referring to section 3 of the LGPL?  The drafters should have  
referenced section 10 there to avoid confusion: section 3 and section  
10 are clearly conflicting provisions with the only indicator of  
precedence being the order (section 3 comes before 10).  I should  
note that this would not be a problem for licenses assigned directly  
by the FSF since they could refer to other documentation that would  
clarify the discrepancy.  It might be a problem for an individual  
programmer who simply adopted the LGPL license and then had to  
enforce it.

Best regards,
Peter