[Mchl]

I also had a similar kind of license in mind. My idea was: the software becomes lincensed under an open source license once any one of these happens:

1. I earn x amount of money out of my work

2. It's n seconds since EPOCH

3. I am pronounced dead by a qualified proffesional or nobody has heard from me for m years.

[kijin]

#1 is difficult for other people to verify.

#3 needs a better definition of "nobody has heard from me". Has anyone heard from you if it becomes widely known that you made a billions dollar from an unrelated business and retired from programming? It will probably work better if you say something like n seconds since the last commit, or since your last public activity on your Github, HN, or Twitter account.

Anyhow, it would be useful to have a standard, legally proven way to make these kinds of promises. Non-lawyers like me trying to be too clever are likely to leave serious loopholes.

[Mchl]

Regarding #1, I'm assuming my own good faith in this :)

#3 in the second clause is indeed tricky, but I suppose it could be worded in legally unambigous way. And anyway I always assumed the dealine in #2 would be no more than three years in the future since the software is first published under these terms.

[PieterH]

The model is simple, each version 'expires' and falls into free software domain after some specific time. If you stop making useful new releases your users fork the last good release. That's it, no need for more complex mechanisms.