RE: Thanks, Ben!
>> But I still don't understand. We're not talking about 5 devices in total. And the app store isn't the only distribution route to these devices.
Well actually, unless you buy development tools and learn how to use them, or you break the licence terms of the software running on the device (and the associated technical measures put in to enforce them), then the AppStore **IS** the only route for putting software on your i<wotsit>.
Whether it's of practical relevance or not, the GPL is quite clear that if a piece of software is under the GPL, then anyone who receives the software is permitted to redistribute both it and derivative works as long as they distribute it with the GPL intact. So it doesn't matter that anyone else can get the program from the AppStore, any one person is contractually allowed (by the GPL) to redistribute it - but Apple's terms specifically prohibit that.
Apple cannot remove the GPL licence from the software, and neither can the person who ported it - without the express permission of every holder of the copyright in the software (in practical terms, everyone who contributed to it). And since Apple weren't prepared to make their store system compatible with the requirements of GPL software - they've removed it.
For Apple this is great - it reduces the competition since they've ruled out any GPL software going on the AppStore. Allowing redistribution as required would have broken their control over users devices. Note the bit about "derivative works" I mentioned ? Well it means that anyone could get GPL software from the AppStore, and would be entitled to the source. They would also be legally entitled to redistribute not only the version on the AppStore, but also derivative works - ie versions NOT approved by Apple.
If the software were under GPL V3, then part of the requirement (added in GPL V3 to prevent a repeat of the TIVO debacle*) would require the distribution also of all information needed to build a working derivative. That means, you would need to distribute enough information to build a binary that would run on an i<wotsit> - and that means being able to sign it without Apple getting involved.
* TIVO took GPL software and complied with the letter of the licence. However, they built a system where you could get the code as required, and you could modify it as required, and you could distribute it as required. Trouble is, they used a signing technique that meant that only official TIVO versions would run.
GPL doesn't sit well with Apple because it doesn't allow them to control the users use of their devices. This test case simply allows Apple a good way to prevent most users of i<wotsit>s from ever using GPL'd software and reliasing how much they are missing.