Yes, clean room approaches are overkill. Obviousness in code has long been found to be a protection against copyright. For instance, you cannot copyright a programme in BASIC that says 10 Print "Hello World" 20 GOTO 10 (And by copyright, I mean prevent anyone else in the world from typing that programme and distributing their copy). One of the great advantage of writing weird, convoluted or just plain dense clever code is that it becomes non-obvious and therefore indubitably covered under copyright. The mere fact that code has been written somewhere, does *not* make it unusable elsewhere. (As an aside, I tend to write plain, straightforward code. Asserting copyright on a lot of it would be hard). One of the great advantages of not doing my coding in the USA is that Stallman would have to come after me in my jurisdiction, not his. Probably a special case of security through obscurity. Usual disclaimer. IANAL. Just interested in these issues from having developed legal support systems (including litigation support systems). As Hannes says, we haven't hit an area of the project where it is an issue yet. But personally, I'm quite relaxed about looking at the Gnu Smalltalk codebase. I'm pretty certain I can re-implement without violating copyright. In the same way I can précis and paraphrase a short story without violating the copyright of the short story. Can any of you tell me the story of Hansel and Gretel without violating the copyright of some recently published re-telling of the tale? I'm pretty certain you could. Please remember that it is much easier to avoid copyright violation than it is to avoid patent violation, in these sorts of cases. None of the Gnu Smalltalk base is patented. Cheers, Euan (back to reading the ICU) On 7 December 2015 at 16:06, Martin Bähr <mbaehr@email.archlab.tuwien.ac.at> wrote:

Excerpts from Martin Bähr's message of 2015-12-07 16:17:28 +0100:

...

randal schwartz suggests a cleanroom approach, though i personally think that is overkill. if a cleanroom approach were really necessary than i would never be allowed to switch jobs because once i have been working on one companys private code i would be tainted for life, as i could accidentally reproduce the same code in my next job.

however, either you get the GNU-smalltalk authors to relicense their unicode classes under the MIT license, or they will need to be rewritten from scratch.

i would suggest asking them in the name of having a common code-base for all smalltalks.

http://lists.squeakfoundation.org/pipermail/squeak-dev/2008-January/123817.h... is worth reading in that context:

So it's mainly an issue of being willing to cooperate. I think all GNU Smalltalk people (almost all?) are and it's also true at least for some Squeak people. If somebody took a package (several thousands lines of code, etc.) wholesale, ported it to Squeak, and licensed it under MIT on SqueakMap that would be copyright violation. But everything can be done "cum grano salis". Nobody is going to sue you if you copy an interface from GNU Smalltalk, reimplement in Squeak (for fun!), but you did look at the method comments in GNU Smalltalk -- and OMG maybe you got a glimpse of the source code just below! Copyright does not protect having similar implementations.

I think we're all for interoperability and for exchange of opinions within the communities.

so there you have the open invitation to go and ask...

and read this http://lists.squeakfoundation.org/pipermail/squeak-dev/2008-January/123838.h... for a good summary on the issue.

greetings, martin.

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