On Sat, Apr 04, 2009 at 02:27:10PM +0200, Lionel Elie Mamane wrote: > On Thu, Mar 19, 2009 at 12:50:45AM +0100, Bill Allombert wrote: > > > RATIONALE (to be amended if necessary): First of all, thanks a lot for your helpful contribution to this discussion. > > 2. This clause is incompatible with section 3. of the Debian Free Software > > Guideline: > > > 2.1 This clause restricts how you can modify the software. > > Doing a simple modification to a AGPL-covered software can require you to > > write a substantial amount of extra code to comply with this > > clause. > > No, it does not. Merely modifying the software does not trigger the > clause. It is triggered only if you offer a service to third parties > using your modified version, or distribute it to others that do. The > latter part (distribute to others that do) is unfortunate; I expect it > is not the intention of the AGPL writers. As written, suppose you modify it and distribute it (in source form) and it reachs the original copyright holder, they can run it and complains if it does not "prominently offer all users interacting with it remotely through a computer network". So in practice the clause is triggered as soon as your version supports such interaction. > Distribution is the same > trigger than what triggers the "copyleft" clauses of the ordinary GPL; > so that trigger cannot in itself be a problem for DFSG freedom. The trigger seems to be "modification" rather than "distribution". > Even if the clause is triggered, the most additional "extra amount of > code" you have to write is provide a link to a download > location. This assumes the program is a CGI script or at least can display text content to the users interacting with it through a network. > Adding exactly one string in a relatively prominent > place. That's not "a substantial amount", especially as typically an > AGPL-covered software will already have the download link or > mechanism, you only have to change the URL or something like that. I'd > be sympathetic to a statement along the lines of: > > Software licensed under the AGPL, that does not itself provide an > "opportunity to receive the Corresponding Source" in the meaning of > clause 13, or is structured such that changing this opportunity to > the source of modified version is not easy, is non DFSG-free, if it > is not free for other reasons (e.g. dual license BSD / AGPL). What if you are reusing only part of the software ? What if your version (but not the original) implement a limited protocol that does not allow to convey arbitrary messages to the users ? > > 2.2 This clause forces the developer modifying the software to incur the cost > > of providing access to the Corresponding Source from a network server > > as long as at least one person is using the software and this for > > all published modifications, even long after the developer stopped using > > the software. > > Ah, I see. That's probably unfortunate wording; the onus should be on > the person providing a service to third parties through the software, > not the developer having made the modification. But indeed, the latter > seems to be what the license is technically saying. I am unsure it is "unfortunate wording": copyright law does not permit to impose arbitrary restriction on usage, and generally free software avoid to restrict usage. Thus they can only restrict distribution (usual) or modification (here). > > 3. This clause is incompatible with section 6. of the Debian Free Software > > Guideline. > > > 3.1 This clause does not allow you to modify the software to perform tasks > > where complying with it is not technically feasible. > > I have difficulties imagining a scenario where "complying with it is > not technically feasible"; also, it seems similar to the GPL's > mechanism of "if you cannot legally obey both the GPL and patent law / > a contract you have signed / ..., then you are not allowed to > distribute at all". That would be "not legally feasible". Not technically feasible would mean you have technical requirement such that: 1) your program must fit in 8kB or 2) your program interact with users in a low-level way that preclude from "proheminently offering" or 3) your program can send notice of "offering source" but clients programs for this protocol generally never display such notice, so it is not "proheminent" or 4) etc. (e.g. a pop3 server can display a message when you telnet to it, but almost nobody ever does that). Cheers, Bill
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