[RFC] Modification history as a source code
Unified copyleft license for free information.
Not every piece of information has a source code, and there are cases
where source code availability can not provide full freedom of usage,
modification, redistribution, and credit.
Define information source as a full history of published modifications
to the licensed piece of information in preferred form for making
Distribution of modified versions of the piece should require that such
source is preserved by respective authors of individual modifications,
and its availability is guaranteed by (a) providing a valid reference to
how the source can be obtained for a charge no more than the cost of
physically performing source distribution, (b) updating the reference on
request in case it becomes invalid, and (c) providing the source on
request in case no other valid reference can be provided.
For software, modification history is already commonly preserved and
published in the form of CVS repositories and other similar version
control systems, and is considered essential to the development process.
In this case, access to modification history already proved itself
instrumental in excercising the freedom of modification.
For documentation and other literary works, additional benefit of
treating modification history as a source code is that all credit is
preserved, and any modifications that change the meaning of a political
or otherwise controversial passage are transparent to the reader. This
should substantially reduce the need for GNU FDL's Invariant Sections.
The main drawback I can see, especially in case of massive scientific
data and multimedia artworks, is increased overhead for storage and
distribution of free information. The issue of distribution is addressed
above by softening the requirement down to at least provide a reference
to the source. The issue of storage is more controversial, all I can
give is my personal opinion that it is fair to expect that creators keep
track of at least their own work, and in case original source is lost
even to its creator, 'form preferred for modification' should be chosen
from forms remaining in existence.
This is not a ready solution, and I expect that debian-legal folks will
be able to punch some holes in it, but I hope it contains some ideas
that can be useful in solving the ultimate task of creating a unified