> From discussions on the Debian list, there's apparently a
> GPL-incompatibility in the Jython license, and some Debian was concerned
> about the inclusion of the Readline stuff (because it links to the GPL'd
> gnu readline library).
The problem derives from the cpython 2.0 license used with jython. From
cpython's own license file:
All Python releases are Open Source (see http://www.opensource.org for
the Open Source Definition). Historically, most, but not all, Python
releases have also been GPL-compatible; the table below summarizes
the various releases.
Release Derived Year Owner GPL-
from compatible? (1)
0.9.0 thru 1.2 1991-1995 CWI yes
1.3 thru 1.5.2 1.2 1995-1999 CNRI yes
1.6 1.5.2 2000 CNRI no
2.0 1.6 2000 BeOpen.com no
1.6.1 1.6 2001 CNRI yes (2)
2.1 2.0+1.6.1 2001 PSF no
2.0.1 2.0+1.6.1 2001 PSF yes
2.1.1 2.1+2.0.1 2001 PSF yes
2.2 2.1.1 2001 PSF yes
2.1.2 2.1.1 2002 PSF yes
2.1.3 2.1.2 2002 PSF yes
2.2.1 2.2 2002 PSF yes
2.2.2 2.2.1 2002 PSF yes
2.3 2.2.2 2002-2003 PSF yes
(1) GPL-compatible doesn't mean that we're distributing Python under
the GPL. All Python licenses, unlike the GPL, let you distribute
a modified version without making your changes open source. The
GPL-compatible licenses make it possible to combine Python with
other software that is released under the GPL; the others don't.
(2) According to Richard Stallman, 1.6.1 is not GPL-compatible,
because its license has a choice of law clause. According to
CNRI, however, Stallman's lawyer has told CNRI's lawyer that 1.6.1
is "not incompatible" with the GPL.
Debian's solution to the readline problem was to not link against
libreadline but instead libedit which is BSD licensed. Bernhard Bablok
was happy to take patches to his readline wrappers to ensure this was
Ben (debian jython maintainer).