D library projects : adopting Boost license

[Walter Bright]

Yigal Chripun wrote:
> I can't see how that's possible. if you contribute to Phobos under Boost 
> license and Phobos is re-licensed under GPL that would mean that any 
> future versions would be GPL but you should be able to fork your 
> original Boost licensed version and release subsequent versions of that 
> under Boost license.
> 
> The project needs to have the ability to adapt its license in the future 
> due to various reasons. case in point is tango: they are discussing 
> changing the license and maybe even go with a Phobos compatible license 
> to help a merger of the two code bases. this requires all contributors 
> (past and present) to agree to this and if somebody cannot be contacted 
> for whatever reason (maybe he lost interest in Tango and D) than his 
> code cannot be re-licensed. Big problem.

I agree. A relicense cannot take away a license granted for the older 
versions - it would only apply to the newer ones.

For the Tango problem, I expect it'll wind up with a few modules that 
cannot be relicensed. Those will remain incompatible with Phobos, and so 
be it. Meanwhile, the rest will be compatible, hopefully that's enough 
and we can resolve these compatibility problems.

Note that Druntime is based on my code I permissively licensed to Tango 
(and anyone else), subsequently extensively modified by Sean and others, 
and relicensed by them back to Phobos. Same goes for math functions by 
Don. So it is possible and productive to do this.