My understanding agrees with Robert's, because the license says "you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version." If any code used pure GPL v2 instead of GPL v2+, then what Adam said would be correct for that code, but I think all of TigerVNC uses GPL v2+ (?)
However, I do feel that it would be poor form to explicitly upgrade the copyright headers on a particular component from GPL v2+ to GPL v3 (thus effectively cutting off any possibility of using the source for that component with GPL v2 projects) without asking any independent developers who contributed. Some of those authors, including Constantin and myself, make their livings off of developing VNC solutions and may not want the fruits of their past labor effectively cut off from their current projects. It would be, IMHO, hypocritical of TigerVNC to upgrade all of its source to GPL v3 without agreement from these other VNC projects that have fed technology into TigerVNC. Doing so would effectively be saying "we want to use your code, but we don't want to let you use any of ours in return." Given that all of the TigerVNC code uses GPL v2+, it would be trivial to make the entire project fall under GPL v3 without preventing code exchange with GPL v2 projects. You'd simply add a header licensed under the GPL v3, and this header would be included when building the code within the context of the TigerVNC Project. Thus, the binaries would fall under GPL v3, but anyone could still easily take the project source, modify it by removing the header in question, and license it under GPL v2. So I guess what I'm saying is-- I don't object to TigerVNC binaries being licensed under GPL v3. I do object to having the source explicitly re-licensed as GPL v3, because it would disallow that source from being shared with GPL v2 projects. There has been a healthy exchange of technology between other VNC projects and TigerVNC, and TigerVNC has obtained numerous benefits from this exchange-- including its current levels of performance. When I started working on it in 2009, it was at about 1/3 to 1/2 the performance of TurboVNC. Now, if you use the right settings, it can be made to perform about the same. In exchange, TurboVNC has been able to adopt (and thus validate and stabilize) some bleeding-edge technologies introduced in TigerVNC, such as the flow-control extensions. In several cases, we have then shared bug fixes in those bleeding-edge technologies back with TigerVNC, thus improving its quality. win-win. On 2/18/13 8:42 AM, Robert Goley wrote: > My understanding is that if the current code is under a GPL2+ license, > that is not required. If it is under a GPL2 only license, then all > contributors must agree to the change. The Linux kernel is an example > of the latter. > > Robert > > > On 02/18/2013 06:35 AM, Adam Tkac wrote: >> On Fri, Feb 15, 2013 at 09:24:13AM +0100, Pierre Ossman wrote: >>> We've done a whole lot of changes since 1.2.0, so I'm starting to feel >>> like it could be time to do another release of TigerVNC. One issue I'd >>> like to revisit for that release is that of an upgrade to GPLv3. >>> >>> Last time we had this discussion, Cendio was for it and so was Adam. >>> DRC was opposed to it though. Since then DRC has moved away from >>> TigerVNC, and we've gotten Brian Hinz as a major contributor of Java >>> code. So what are the opinions of the current development group? Cendio >>> is still very much for a change. >> Personally I have no problem with GPLv2 -> GPLv3 change. However if I >> understand >> licensing correctly, everyone who contributed to TigerVNC in past must agree >> with the change, which includes also Constantin Kaplinsky and his TightVNC >> crew >> and probably also RealVNC and their crew. But as I wrote above, I'm not 100% >> sure about this. >> >> Regards, Adam ------------------------------------------------------------------------------ The Go Parallel Website, sponsored by Intel - in partnership with Geeknet, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials, tech docs, whitepapers, evaluation guides, and opinion stories. Check out the most recent posts - join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Tigervnc-devel mailing list Tigervnc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tigervnc-devel
