Nothing to add to the particular question, but I'm writing to express how much I disagree when you use adjectives such as "viral" or nouns such as "infection" to describe GPL. I'm a FSF supporter for a long time, and while I'm used to people choosing not to use free software licenses for the sake of reaching as many business opportunities as possible, I care about the ethics behind the free software movement. I respect people not caring about that fundamental part of the Free Software movement, but I cannot remain silent when everybody seems to share the same unfortunate interpretation of what the GPL is about. 2017-09-17 18:59 GMT+02:00 Ben Coman <btc@openinworld.com>:
On Sun, Sep 17, 2017 at 7:00 PM, stephan <stephan@stack.nl> wrote:
On 17-09-17 06:59, Jimmie Houchin wrote:
And the GPL not be viral in my app provided I only use the GPL library
and am not modifying it in my app.
Do I understand this wrong?
Yes. With GPL everything is now GPL. With LGPL, as long as you only link to it, the viral aspect is limited to the library. In Pharo, that means you can use UFFI to connect to LGPL libraries, and you can probably create plugins. Loading smalltalk libraries that are LGPL is not exactly the same as linking, there is no clear boundary between compile-time and run-time, as everything is in the image. That makes the LGPL difficult to interpret in the smalltalk case, and potentially viral.
+1.
On Sun, Sep 17, 2017 at 6:09 PM, Hilaire <hilaire@drgeo.eu> wrote:
Regarding porting GPL software, I guess you mean rewriting with Smalltalk, you should be free to license it as you want, for example as MIT. AFAIK there is no evil restriction as "seen the code" under the GPL.
It is not as clean as that. Many consider "seen the code" to implicate "derived code". Whether a court of law agrees with this or not is not what you should consider. The best advice I received from a lawyer is that winning in court (sometimes after years of effort) is still a loss, so you should position yourself so that no one even thinks they can take you court.
For library, alternative is LGPL and I read this interesting note: One should note that subclassing a Java (or other OO) class licensed under the LGPL is regarded as a use of an interface of a library comparable to a function call of a library. It is not regarded as a modification of the original class. Therefore the subclass does not fall under the requirements of the LGPL.
The definitive reference of Java + LGPL is https://www.gnu.org/licenses/lgpl-java.en.html which says: "The typical arrangement for Java is that each library an application uses is distributed as a separate JAR (Java Archive) file. Applications use Java's âimportâ functionality to access classes from these libraries ... The LGPL permits this distribution ... Applications need only follow the requirements in section 6 of the LGPL"
but a Smalltalk Image runs foul of section 6 requiring... "A suitable [shared library] mechanism ... that (1) uses at run time a copy of the library already present on the user's computer system, rather than copying library functions into the executable" where an Image is considered to be the "executable".
So incorporating LGPL Smalltalk code into an Image causes all code in the Image to be infected with the LGPL.
So using a LGPL library, even extending it, does not force the user to be in the GPL family license.
Using LGPL C libraries is fine and doesn't infect your Smalltalk code. Using LGPL Smalltalk libraries does infect all Smalltalk code in your Image. The concern is contributing a bug fixed in Pharo code from an infected image technically infects the whole of Pharo - although you are free to update a clean image with the same bug fix and contribute from there - but thats an awkward process.
The only restriction is the receiver should be capable to update the LGPL package independently of the application using the package. Anyway, I don't think you should worried about porting GPL/LGPL libraries as long as your are rewriting it. You can license it under MIT. Then LGPL is also possible.
The term "port" clearly implies "derived" so you cannot arbitrarily re-license just by changing implementation languages. Otherwise for example a GPL library could be relicensed by one team porting from C to Python, then a second independent team ports from Python back to C subverting the original copyright.
=============== Hmmm... actually refreshing myself with the newer license texts just now I notice GPL 3 has added some interesting definitions the GPL 2 lacks...
The âCorresponding Sourceâ for a work ... does not include the work's System Libraries
The âSystem Librariesâ of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form.
A âMajor Componentâ, in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it.
A âStandard Interfaceâ means an interface that ... is widely used among developers working in that language.
which seems to open the door to a strong argument** that Pharo is such a Major Component protected from even a full GPL3 coded application being loaded and run - i.e. you could fix and contribute Pharo code directly from such an Image - but other non-GPL Smalltalk libraries you mix in may not be similarly protected. But it still seems a grey area with compliance easier to manage using nonCopyLeft licenses.
cheers -ben
** You'd probably want the FSF to directly issue a statement on this.