GPL vs LGPL, in the context of adns
-----------------------------------
-Several people have asked me to release adns under the GNU Lesser
+Several people have asked me to release GNU adns under the GNU Lesser
General Public Licence (LGPL, formerly the Library GPL) instead of the
`stronger' GPL. This file is intended to answer most of these
questions. If you still have questions or comments, please mail me at
<adns-maint@chiark.greenend.org.uk>.
Typically there are two or three kinds of situation where people make
-this request: the first is where someone is developing a proprietary
-program and wishes to make use of adns but doesn't wish to make their
-program free software. The second case is where a free software
-project is currently using an MIT-like licence or the LGPL and fear
-`GPL infection'. The third case, which often overlaps with the
-second, is where another free software project currently using a
-GPL-incompatible licence, wishes to use adns.
+this request: the first is where another free software project
+currently using a GPL-incompatible licence, wishes to use adns. The
+second case, which often overlaps with the first, is where a free
+software project is currently using an MIT-like licence or the LGPL
+and fear `GPL infection'. The third case is where someone is
+developing a proprietary program and wishes to make use of adns but
+doesn't wish to make their program free software
-1. Proprietary applications of adns
------------------------------------
-
-So, let me get this straight. You're writing a proprietary
-program, by which I mean that you will not be distributing source code
-and not allowing users to modify and share your software; most likely
-you are doing this for your own (personal or corporate) financial
-gain.
-
-However, you want to take advantage of adns, software which I have
-spent my time and effort on, and which I release as free software so
-that everyone can improve, share and use it.
+1. GPL-incompatible free software licences
+------------------------------------------
-Don't you think that is a little hypocritical ? I'm sorry, but I
-don't want you to just take my nice convenient software, without
-giving something back to the free software community or giving the
-same rights to your users as I do to you.
+Regrettably, there are a number of free software licences (and
+semi-free licences) in existence which are not compatible with the
+GPL. That is, they impose restrictions which are not present in the
+GPL, and therefore distributing a whole work which contains both such
+a program and a GPL'd program is not possible: either the combination
+would have to be distributed under the GPL (violating the restrictions
+made by the original author), or under the GPL-incompatible licence
+(violating the GPL).
-If you really aren't the nasty kind of person I've described here, for
-example if you have a good reason other than your own selfishness for
-wanting to restrict distribution of your program, then perhaps you
-should contact me to discuss it.
+I may be prepared to make exceptions for such a licence. Please
+contact me at <adns-maint@chiark.greenend.org.uk> with the full text
+of the GPL-incompatible licence. However, I would usually prefer it
+if you could use a GPL-compatible licence for your project instead.
2. GPL-avoiding projects (MIT licence, et al)
their software, or the in the case of some free libraries, the LGPL,
which allows proprietary applications. I have to say that I think
these people are misguided, but that doesn't mean that they don't have
-a perfect right to.
+a perfect right to do that.
Some of these people think that merely writing to an interface
provided by GPL'd software will cause their program to become GPL'd
too, even if they don't distribute the GPL'd software. I don't think
-this is the case. I'm perfectly happy for non-GPL'd software to refer
-to adns in its source code. However, I think that exectuables (or
-compiled libraries) which contain or are dynamically linked against
-adns must be GPL'd; likewise executable programs (whether compiled or
-in an interpreted language) which require utilities from adns to
-function properly must be GPL'd.
+this is the case. I'm perfectly happy for non-GPL'd but
+GPL-compatible software to refer to adns in its source code. However,
+I think that exectuables (or compiled libraries) which contain or are
+dynamically linked against adns must be GPL'd; likewise executable
+programs (whether compiled or in an interpreted language) which
+require utilities from adns to function properly must be GPL'd.
So, you can distribute your non-GPL'd program source which needs adns
-to compile, but people who wish to distribute binaries must do so
-under the terms of the GNU GPL. This may make sense for some
-GPL-avoiding free software projects; people can still make proprietary
-programs from your code, provided that they make some provision to
-replace adns with something whose copyright allows proprietary
-versions.
+to compile (provided it's under a GPL-compatible licence), but people
+who wish to distribute binaries must do so under the terms of the GNU
+GPL. This may make sense for some GPL-avoiding free software
+projects; people can still make proprietary programs from your code,
+provided that they make some provision to replace adns with something
+whose copyright allows proprietary versions.
However, this doesn't make much sense for the authors of LGPL'd
libraries. All I can say to them is to ask which is more important:
To help the case of LGPL'd libraries for which adns is not a vital
component - for example, a library which provides access to other
libraries so that programs which use it need only use certain parts,
-I have release adns.h (just the public header file) under the LGPL as
+I have released adns.h (just the public header file) under the LGPL as
well as the GPL. See the copyright notice in adns.h for details.
Note that this will not help you if it adns is essential to the
functioning of your library, because all programs using your library
at http://www.fsf.org/philosophy/why-not-lgpl.html
-3. GPL-incompatible free software licences
-------------------------------------------
-
-Regrettably, there are a number of free software licences (and
-semi-free licences) in existence which are not compatible with the
-GPL. That is, they impose restrictions which are not present in the
-GPL, and therefore distributing a whole work which contains such a
-program and a GPL'd program is not possible: either the work would
-have to be distributed under the GPL (violating the restrictions made
-by the original author), or under the GPL-incompatible licence
-(violating the GPL).
-
-I may be prepared to make exceptions for such a licence. Please
-contact me at <adns-maint@chiark.greenend.org.uk> with the full text
-of the GPL-incompatible licence. However, I would prefer it if you
-could use a GPL-compatible licence for your project instead.
-
---- Ian Jackson ...
-
-
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