Your questions about what makes a work "derived" from a GPLed work are good questions. Unfortunately, laws are not uniform on this; in the US, there are two or three different ways to analyze whether one work is derived from another copyrighted work, and I imagine most other countries have their own rules (at least slightly different from the US's) to determine this. In the case of a shell script, the point is likely moot because the script is its own source code.
Török Edvin writes: > To be "safe", and not violate the GPL, which of the following should I do: > - A link to where the original sources can be downloaded from > - Include the sources of xpdf/xdialog > - Host the sources of xpdf/xdialog on the company's webserver > > Should I also: > - Write a statement in a README/COPYRIGHT file, enumerating the > included GPL software, and their copyright > - Contact upstream, to let them know we use their software The GPL specifically disallows the first option for commercial distribution unless you are the one hosting the source code (and you provide it for at least three years after your most recent distribution of binary files). The easiest way to satisfy the GPL is to include the complete source code for the GPLed works that you distribute on the CD, which I think is your second option. Whichever option you choose, you must include a copy of the GPL on the CD and identify the GPLed software. Notifying the upstream maintainer is polite but not required by the GPL. > P.S.: > If I make changes to a GPL program, is it enough if I submit the > changes upstream, or do I have to offer the patch (on the CD/on the > web)? Neither by itself satisfies the GPL. The GPL requires that the binary-code recipient (be able to) get the complete modified source code. Michael Poole
