This is the relevant entry from the GPL FAQ: http://www.gnu.org/licenses/gpl-faq.html#IfInterpreterIsGPL
To quote: [quote] If a programming language interpreter is released under the GPL, does that mean programs written to be interpreted by it must be under GPL- compatible licenses? When the interpreter just interprets a language, the answer is no. The interpreted program, to the interpreter, is just data; a free software license like the GPL, based on copyright law, cannot limit what data you use the interpreter on. You can run it on any data (interpreted program), any way you like, and there are no requirements about licensing that data to anyone. However, when the interpreter is extended to provide “bindings” to other facilities (often, but not necessarily, libraries), the interpreted program is effectively linked to the facilities it uses through these bindings. So if these facilities are released under the GPL, the interpreted program that uses them must be released in a GPL- compatible way. The JNI or Java Native Interface is an example of such a binding mechanism; libraries that are accessed in this way are linked dynamically with the Java programs that call them. These libraries are also linked with the interpreter. If the interpreter is linked statically with these libraries, or if it is designed to link dynamically with these specific libraries, then it too needs to be released in a GPL-compatible way. Another similar and very common case is to provide libraries with the interpreter which are themselves interpreted. For instance, Perl comes with many Perl modules, and a Java implementation comes with many Java classes. These libraries and the programs that call them are always dynamically linked together. A consequence is that if you choose to use GPL'd Perl modules or Java classes in your program, you must release the program in a GPL- compatible way, regardless of the license used in the Perl or Java interpreter that the combined Perl or Java program will run on. [end quote] Since Sage has bindings to GPLed libraries, i.e. libSingular to make one example, according to the FSF a Sage program would be derived from a GPLed combined work and would have to be licensed GPL compatible *if distributed*. So, in the end it depends if you share the FSF's interpretation of the GPL to be that far reaching or not. IMHO they are overreaching, but IANAL on one hand and on the other hand have no problem licensing anything I write in Sage under the GPL. Cheers, Michael --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
