If that's the case, we have a much larger problem. From the "copyright" file:
This software is copyright (c) Paul Graham and Robert Morris. Permission
to use it is granted under the Perl Foundations's Artistic License 2.0.
This is from arc2.tar (and thus Anarki as well). Thus if that's true about the Artistic License, all of Anarki is in violation. According to Wikipedia (http://en.wikipedia.org/wiki/Artistic_License), however, the Artistic License 2.0 is both free and open source---in fact, it's GPL compatible, and perl itself is dual-licensed under both of said licenses. Thus, I would think we would be OK.
It's a bit late/early and IANAL, but my reading of the Artistic License is that we are OK given section 4. Section 4 says that we can distribute modified versions of the source provided we document the differences and either: (a) make the modified version available to the original creator under the original license; (b) ensure that one can install both the modified and original versions separately and that the modified one has a different name; or (c) allow redistribution of the source under either this license or another free license. We're definitely doing (a) and (c) and we're probably doing (b), so if I understand this correctly, we should be in the clear.
Thoughts on this interpretation? This is much bigger than just one library, after all...
Somewhat annoying, as doing a 'diff' is probably not enough.
It'll also become slightly messy if pg's statement from a month ago becomes true, and there will be new versions of arc coming out in october / november. If we pick up features from different versions of arc, would the changes compared to arc2, as well as the changes compared to arc3 need to be documented.
I guess the value of forcing good documentation of the changes is that it becomes easier for pg to distill a new arc version out of the mutants that the community is spawning, as they'll have their features well documented.
