Licensing Mixxx and Code Rippers??

General Mixxx discussion.... discuss

Moderator: garth

Licensing Mixxx and Code Rippers??

Postby mimizzik » Tue Apr 10, 2012 3:20 pm

Hi All,

I have joined this forum to assist in my education of licensing for open source products. I am a gaming nut and know little about software/coding. Games are the limit of knowledge and passion :oops:

I found myself in a somewhat heated argument with a co-worker the other day, who is a software developer. I did get a little rattled....

He stated that it is possible for someone to take an open source project, (such as Mixxx - we were talking about), re-skin it, make some small changes, remove any reference to the open source project, re-brand it and sell it to the general public without permission!

He further stated that source-code and copyrights cannot be identified from a user-ready software download, should someone wish to steal code (such as Mixxx) for their own commercial gain.

Can this actually be done? Surely there is something preventing greedy code thieves from selling an open source product?

I had little fodder to use in this argument and left looking like an idiot. Could someone please help to understand a little about this; it would be highly appreciated.

Posts: 2
Joined: Tue Apr 10, 2012 2:59 pm

Re: Licensing Mixxx and Code Rippers??

Postby rryan » Tue Apr 10, 2012 5:46 pm

Hey there,

Yes sadly this is possible and it has already been done to Mixxx. If you want some examples see the programs: TinyDJ (tiny dj dot net), Digital DJ Pro (music-oasis dot com slash download slash Audio slash Digital-DJ-Pro), and DJ Mixer Studio (djmixerstudio dot com). I won't link to them here so they do not get any link-credit from and please do not Google for them either.

These are just clones of Mixxx, re-branded. This is possible due to Mixxx's open-source license (the GPLv2). Open-source is about sharing and re-using code so this is one possible use of the Mixxx codebase. In each of these cases, due to the requirements of the GPLv2 these re-branded versions of Mixxx must also provide the source code for all of their modifications to Mixxx. We have been in contact with these companies to make sure that they do follow the requirements of the GPL.

Contrary to popular belief it is totally legal to sell open-source software (even under the GPL). If you sell it, you must provide the source code along with the software also licensed under the GPL. The buyer of the software has every right to turn around and offer the source to that software to the world for free since she received that source code under the GPL. This means that selling open-source software is hard to make profitable. The most common thing you'll see is an eBay seller selling a "SuperDJ" software that is just Mixxx rebranded. An unsuspecting eBayer might buy this for $1 and never know that it's actually Mixxx. This business model relies on the buyer not knowing any better.

If someone were to violate our copyright -- to take our code and distribute a modified version of it without releasing their modifications under the GPL, then we would have a valid copyright violation complaint against that person/business. The GPL-violations project is an organization of pro-bono lawyers who pursue GPL violators so it is not unheard of for GPL violators to be brought to justice.

There is a separate issue of trademark. If someone were to distribute Mixxx without re-branding it then they would be violating our trademark and we could go after them that way. In the past, we asked distributors of re-branded versions of Mixxx to remove our trademarked materials (e.g. skins, logos, etc.) from their re-distributed version of Mixxx. There is precedent for this -- see "firefox vs. iceweasel".

Finally, to address your point of not being able to tell if a piece of software contains code from the Mixxx project -- there are various forensic tests you can do. We have done symbol analysis of various major DJ software (e.g. VirtualDJ) and have been able to detect from the symbols they left in their binaries that they have stolen code from open-source projects such as FFMPEG without attribution or following license requirements. Beyond this you can do more advanced things to test if the code of a program was taken from another. In the case of wholesale clones of Mixxx it is painfully obvious to a Mixxx developer. There are so many quirks that are specific to Mixxx that would allow you to uniquely tell that it was Mixxx under the hood even if the developer had gone to great lengths to conceal it.

Hope this helps,
The Mixxx Manual, Wiki and FAQ are the best place to start for documentation and support.
Please report any bugs you find to our Bug Tracker.
Mixxx Developer
Posts: 1335
Joined: Thu Mar 26, 2009 12:14 am
Location: California

Re: Licensing Mixxx and Code Rippers??

Postby mimizzik » Tue Apr 10, 2012 11:48 pm

Wow RJ,

Thanks for the extensive and detailed response. I will certainly have some ammunition for when I bring this up at work tomorrow.

Surely this kind of thing could be avoided by offering Mixxx to developers (who are out to make money) via some kind of license?

I think that if there was some generic, cost effective way of licensing this project, where people did not have to credit Mixxx, it could save a lot of heartache and earn you guys some easy money. :idea:

Just an outsiders view... Interesting though

Posts: 2
Joined: Tue Apr 10, 2012 2:59 pm

Return to General Discussion

Who is online

Users browsing this forum: Google [Bot] and 15 guests