IANAL and this is not legal advice.
One of the big grey areas in the GPL is the question of
what a "derivative work" is. What I have heard is that
there is rather little case law on this question, and so
there are a lot of question marks. Lots of those question
marks are about what does and does not constitute combining
components into one whole work.
This memory is verified by the GPL FAQ which
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
The distinction between interacting but separate and
combined is very fuzzy. But legally it matters a lot
because it is the line between where you have copyright
over the whole, and where you don't. Since the GPL by
structure only of gives back some permissions taken away
by copyright law, unless copyright applies the GPL has no
If this seems very arbitrary, it is. After all copyright
started in the English-speaking world as a grant of control
to authors so that publishers could get what they used to
get through censorship laws...
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
- a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.
| & || & |
| < || < |
| > || > |
| [ || [ |
| ] || ] ||