[EMAIL PROTECTED] wrote:
When I download an ISO of a Linux distro, I get many programs under
many incompatible licenses in a single file. Various lawyers have
clearly concluded that it's 'safe' to do this. So, the Eclipse plugin
author is being paranoid.
No. The GPL specifically allows for "mere aggregation" of programs, such as
bundling two separate programs on the same CD, but disallows distribution of a
"derived work" unless that derived work is under the GPL. The author of the
Eclipse darcs plugin is legally disallowed from shipping a version of darcs
that comes with the CPL'ed Eclipse darcs plugin.
I know this doesn't seem sensible, but that's the way it is.
This also means that if I hook up darcs and the darcs eclipse plugin together
(which has so far proved to be a non-trivial task...), I am technically
forbidden to give the resulting setup to a friend.
Similarly untrue, unless you actually have to compile/link them together.
No. The GPL doesn't restrict you from compiling/linking things together when
the result is not GPL'ed. It restricts you from creating a derived work when
the result is not GPL'ed. How that derived work fits together, such as by
compiling/linking, by using an interpreter, by using "exec", etc. is
irrelevant to the requirement to GPL the result.
Apparently, you don't understand what a derived work is. A plugin that
calls darcs as a seperate application (ie, fork and exec) is not a
derived work. Derived work implies using source code from the existing
work.
From the GPL FAQ:
If a program released under the GPL uses plug-ins, what are the
requirements for the licenses of a plug-in.
** It depends on how the program invokes its plug-ins. If the program
uses fork and exec to invoke plug-ins, then the plug-ins are separate
programs, so the license for the main program makes no requirements for
them. **
If the program dynamically links plug-ins, and they make function
calls to each other and share data structures, we believe they form a
single program, which must be treated as an extension of both the main
program and the plug-ins. This means the plug-ins must be released under
the GPL or a GPL-compatible free software license, and that the terms of
the GPL must be followed when those plug-ins are distributed.
If the program dynamically links plug-ins, but the communication
between them is limited to invoking the `main' function of the plug-in
with some options and waiting for it to return, that is a borderline case.
What is the difference between "mere aggregation" and "combining two
modules into one program"?
Mere aggregation of two programs means putting them side by side on
the same CD-ROM or hard disk. We use this term in the case where they
are separate programs, not parts of a single program. In this case, if
one of the programs is covered by the GPL, it has no effect on the other
program.
Combining two modules means connecting them together so that they
form a single larger program. If either part is covered by the GPL, the
whole combination must also be released under the GPL--if you can't, or
won't, do that, you may not combine them.
What constitutes combining two parts into one program? This is a
legal question, which ultimately judges will decide. We believe that a
proper criterion depends both on the mechanism of communication (exec,
pipes, rpc, function calls within a shared address space, etc.) and the
semantics of the communication (what kinds of information are interchanged).
If the modules are included in the same executable file, they are
definitely combined in one program. If modules are designed to run
linked together in a shared address space, that almost surely means
combining them into one program.
** By contrast, pipes, sockets and command-line arguments are
communication mechanisms normally used between two separate programs. So
when they are used for communication, the modules normally are separate
programs. But if the semantics of the communication are intimate enough,
exchanging complex internal data structures, that too could be a basis
to consider the two parts as combined into a larger program. **
--
--Max Battcher--
http://www.worldmaker.net/
The WorldMaker.Network: Support Open/Free Mythoi. Read the manifesto @
mythoi.com
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