Item — HN Reader

For the incompatible licenses, Microsoft can:

1. Buy the rights from the original owners (if you are the owner, you can re - license your code under a different license).

2. MS can reimplement from scratch the problematic pieces of code.

3. MS can hire someone to write these missing pieces for them.

1 comments

How does relicensing work?

If I'm the writer of a GPL'd piece of software can I just decide to make it MIT one day?

What happens if I die tomorrow, could that code still be relicensed eventually?

What happens when there is no clear owner?

Yes, as long as you retain the copyright of the code you wrote (i.e. didn't explicitly assign it to someone else, or write it as a work for hire) then you can relicense it under whatever you wish at any time. You could make it available under GPL, CDDL, MIT, and the Beerware license all at once.

This stuff is relatively simple at its core. Copyright says, "You may not redistribute this work without permission from the copyright holder." An open source license says, "I grant you permission to redistribute this work, as long as you follow these conditions." Relicensing is just a matter of making another statement like that with different conditions.

If you die tomorrow, then the copyright transfers to your heirs, who could then do all the stuff you used to be able to do.

If there's no clear owner, then life becomes interesting. If there once was a clear owner who released the stuff with a license, that license is still valid, but relicensing isn't possible unless someone can demonstrate that they're the owner. If there was never a clear owner then you can't really use the stuff, although if you're brave you could proceed under the theory that if nobody claims ownership there is nobody to sue you.

I think the general consensus is that if you authored 100% of the code yourself, you could always change the license (but people could fork the latest version under the old license and keep going, as happened with X.org), but it you ever took any patches/pull requests/contributions without also receiving a copyright assignment, you need to hunt down every single contributor to agree to a license change. I think that happened with Mozilla and VLC, whilst for Linux it would appear that several core contributors have explicitly refused to re-license (for example to change from GPL2only to GPL2+).

Other examples include MySQL, which was dual-licensed GPL and commercial, and KDE/Qt which also had a dual-licensing (and then a re-licensing).

If all contributors also accept to transfer copyright/ownership up-front, re-licensing is easier.

I'm guessing re-licensing after death would require waiting whatever period (70+ years?) for copyright to expire.