GPL2 vs GPL3

Some people don't like the GPL3 and prefer to use the GPL2 license. We use GPL3. Just in case I missed something I just finished comparing the GPL3 to the GPL2 in detail and confirmed that we like the GPL3 better.

The main differences:

• it closes the "device" loophole: licensees can't distribute a GPL3 as part of a device (e.g., Tivo or iPhone) that doesn't allow you to run modified versions.
• it has teeth: it a licensee violates the license you can permanently terminate their license. You notify them, and if it's a first offense they have 30 days to cure the violation. If they fail to comply, they are forever prohibited from distributing your GPL3 program. In other words, fixing the violation doesn't provide them a new license to the program. This is a powerful sanction.

The usual protections GPL2 apply, though they have been clarified a bit:

• the license kicks in when you distribute the work to third parties
• licensees can't remove copyright notices, sub-license under different terms, etc.
• any modifications/patches have to be distributed under your license
• modified versions have to be marked as such
• copyright holder doesn't have to allow anyone to use his trademarks. This means you can use trademark law to force them to use a different name for the modified program. (e.g., IceWeasel)
• if a licensee has patents that cover your work, accepting the license means they give up their rights to enforce their patents.