[winswitch] [Xpra] Android client

Antoine Martin antoine at nagafix.co.uk
Wed Jun 24 16:30:49 BST 2015

On 24/06/15 19:47, Jakub Księżniak wrote:
> Hi,
> Thanks for all feedback. I've read a bit about licensing and I came up 
> with some thoughts.
> 1. To write a fully functional client application, a network protocol 
> must be implemented to communicate with other side. In this case, the 
> only available reference is a source code of Xpra and wiki pages.
> 2. Unfortunately the documentation found on the wiki is not 
> sufficient, as for example I had to learn from Java sample code what 
> capabilities must be sent in a Hello packet in order to connect to the 
> server. Without it, it's impossible to get a reasonable response, not 
> to mention about other features.
Yes, that's unfortunate.
> 3. If the Xpra protocol was described in some official document like 
> RFC6143 for the RFB protocol, then I could base on it instead of the 
> Xpra sources.
Indeed, the documentation on the wiki is fairly complete if not up to 
date, it could be turned into an RFC, given time...
The flags
> To sum up, it appears that my code is a "derived work" and thus the 
> only option is to choose a GPL license. :-(
That is my interpretation - but not necessarily the right one!
> Then, I'll change license information on Github with my next commit.
I really don't like this outcome because it sounds like I am forcing a 
license (GPL) on your code, one that I didn't even choose to begin 
with... and I have no personal preference for it in any case.
So I hope that someone else can suggest a way out of this conundrum.


PS: I found the O'Reilly book " Intellectual Property and Open Source":
very relevant to this discussion. In particular chapters 12 and 13.

> Thanks,
> Jakub Księżniak
> 23 cze 2015 10:02 "Antoine Martin" <antoine at nagafix.co.uk 
> <mailto:antoine at nagafix.co.uk>> napisał(a):
>     Hi,
>     On 22/06/15 22:47, Jakub Księżniak wrote:
>     > Hello,
>     >
>     > I've been writing an Android Xpra client for some time now
>     (maybe you
>     > remember our previous conversation on a mailing list). It took
>     me quite a
>     > lot of time to make a barely working app, but here it is. :) You can
>     > download source code from Github and build it by yourself:
>     > https://github.com/jksiezni/xpra-client
>     Good stuff!
>     I think this should replace the current "official" Android client,
>     which
>     was never more than a quick and dirty proof of concept.
>     > Moreover, I've got some concerns regarding licensing. I'd like
>     to share my
>     > code on terms of Apache License 2.0 and I'd like to know if it
>     is OK with
>     > you.
>     This is not entirely up to me and IANAL.
>     My understanding is that if you've developed your code using a "clean
>     room design", then you can use any license you want for your code.
>     Otherwise, you probably fall under the "derived work" and
>     therefore are
>     bound by the GPL.
>     I did write a lot of information on the wiki to try to make it
>     easier to
>     implement new clients without referring to the actual code (though
>     most
>     of it may be slightly out of date), starting here:
>     http://xpra.org/trac/wiki/NetworkProtocol
>     To make matters more complicated: although I would be quite happy to
>     re-license all of my code under a different license, which would cover
>     100% of the Java client for example (assuming you read some code and
>     that this is what you used)... but then again, by definition (since I
>     wrote a large portion of the GPL2+ xpra code) not using a "clean room
>     design", I don't think I could re-license it under anything less
>     restrictive than the GPL. And even if this was possible, I'm not sure
>     you could apply it retroactively - but maybe?
>     And it also depends what jurisdiction you fall under... etc.
>     > Also, I've added an Xpra icon to the android project, which
>     makes an app
>     > much more recognizable. But it requires your permission, if I'm not
>     > mistaken. So, do you agree, to use the Xpra icon in this project?
>     No problem from me here... this icon is a bit too close to the
>     official
>     X11 icon, and I should probably have sought permission from them...
>     I just wanted to get something done quickly, many years ago, and
>     did not
>     foresee the project getting as successful as it is now.
>     The project also covers a lot more than just plain-X11 servers now, so
>     this may be a good time to come up with a better icon?
>     (there are also requirements for 1024x1024 to get into the Apple
>     appstore)
>     > Any feedback would be appreciated.
>     I'm hoping others can chime in, hopefully with more experience in
>     this area.
>     Cheers
>     Antoine
>     PS: Some pointers:
>     https://en.wikipedia.org/wiki/Clean_room_design
>     http://hoviblog.blogspot.fr/2008/10/clean-room-defeats-software.html
>     " For purposes of proving such a claim of copyright or trade secret
>     misappropriation, it is not necessary to prove that actual copying
>     occurred. It is sufficient to show that (1) the accused party had
>     access
>     to the code, and (2) the accused party's code is substantially similar
>     to the claimant's code."
>     I have no idea what "substantially similar" means here!
>     >
>     > Regards,
>     > Jakub Księżniak
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