Mozilla toont iPad-browser Junior

The most obvious conflict between the App Store and the GPL is the third freedom – "the freedom to redistribute copies so you can help your neighbor."

There has been lengthy discussion about this issue, with people advancing arguments on both sides. Sadly, the bottom line is this: firstly, it's a gray area, and secondly, it's unlikely to ever be certain one way or the other without a legal trial. We're unlikely to ever get a trial because Apple (as software distributor for all App Store programs) is probably not going to ever go to bat for an Open Source package in a courtroom. So the practical outcome is that the App Store and the GPL are incompatible until proven otherwise, and it's probably never going to be proven otherwise. Apple certainly thinks so, or it wouldn't have removed VLC (and other Open Source apps like GNU Go) from the App Store.

The Free Software Foundation, authors of the GPL, also doesn't think so. The argument revolves around the following clause in the GPL v2:

Each time you redistribute the Program (or any work based on the Program), the recipient automatically receives a license from the original licensor to copy, distribute or modify the Program subject to these terms and conditions. You may not impose any further restrictions on the recipients' exercise of the rights granted herein.

Now consider the App Store User Agreement:

(i) You may download and sync a Product for personal, noncommercial use on any Apple-branded products running iOS ("iOS Product") you own or control.

(ii) If you are a commercial enterprise or educational institution, you may download and sync a Product for use by either (a) a single individual on one or more iOS Product you own or control or (b) multiple individuals, on a single shared iOS Product you own or control.

(iii) You shall be able to store App Store Products from up to five different Accounts at a time on compatible iOS Products.

The FSF's legal council takes the stance that these are restrictions on what the user can do with software obtained from the App Store, so that's immediately a breach of the GPL. It doesn't matter that the iOS port of VLC is free. In fact, it might be clearer to imagine it wasn't.

Consider if Applidium had charged $5 for their port of VLC, while also distributing the full source on their website. Nothing in the GPL precludes developers from charging for derived works, so that's fine and above board. Mike buys a copy for $5, and he wants to give a copy to his friend Steve (as is his right under the GPL), but he can't. Steve is free to pay another $5 for his own copy, but he can't get it from Mike; he has to go back to Apple.

In this instance VLC was free, so Steve doesn't mind that he has to get a free copy; but that might not be true of some future software, and in any event, it doesn't matter because the legal terms of the GPL do not allow exclusions just because a piece of derived software happens to be free.

Note that the FSF page makes reference to only installing apps on five iOS devices at once as another restriction of user's rights; this appears to be an error, as this statement only appears in the iTunes content part of the User Agreement and doesn't apply to iOS apps. It's also possible that the iTunes User Agreement was modified after the FSF article was published.