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From: Alexander Terekhov (terekhov_at_[hidden])
Date: 2007-03-21 07:48:14

Martin Wille wrote:

[... "combining" ...]

> However, it is not possible to relicense GPLed code under BSL (unless
> you're the copyright holder). The GPL is a lot less free than the Boost


Under the U.S. Copyright Act, a combination of a computer program with
other software results in the preparation of a derivative work only if
the combination (a) is sufficiently permanent, (b) contains significant
and creative portions of the other software, (c) is creative in its own
right, and (d) involves significant and creative internal changes to
the other software. Most software combinations fail to meet one or more
of these requirements and constitute either compilations, collective
works, or noncopyrightable aggregations, and neither affect copyright
owners’ adaptation rights under Section 106 of the U.S. Copyright Act.

Software combinations involving dynamic links usually lack permanency,
combination creativity and internal changes. Even software combinations
through static links do not necessarily affect adaptation rights,
because such linking often results in the creation of a compilation or
non-creative aggregation of programs or sub-programs. Nevertheless,
under the U.S. Copyright Act, software developers typically have to
obtain a license before they may combine programs through static
linking because this affects the duplication rights of the linked
program’s copyright owner. Also, adaptation rights may be affected
where software combinations (regardless of the code linking method)
result in significant and creative changes to original screen output
(e.g., in the context of computer games).

Under common commercial licensing conditions, end users typically
receive an express or implied license to execute proprietary software
in combination with other software, regardless of whether the
combination would qualify as a derivative work. Under the GPL, end
users are free to combine GPLed code with any other code. Developers
and distributors do not have to be concerned about contributory
liability, so long as they distribute add-on software separately and
the end-users are not legally restricted in combining the intended
programs with the add-on software.

Anybody who wants to distribute programs in combination and alongside
with GPLed code, however, will have to closely examine the reach and
consequences of the various conditions and restrictions in the GPL. The
term “derived work” in the GPL should be interpreted to mean
“derivative works as defined by copyright law,” and as a consequence,
most programs could be distributed in combination with dynamically
linked GPLed code without the necessity of subjecting the linking
programs to the GPL.

It seems possible, however, that courts may interpret the GPL in a
broader way, which would increase concerns regarding the validity of
the GPL under copyright misuse doctrines, competition laws and unfair
contract term laws; such concerns can be greater or smaller depending
on the circumstances of the licensing parties and jurisdictions
involved. If such broad interpretations were to prevail––but the
resulting validity concerns were not––the software industry might move
more generally to GLP-like restrictive licensing practices that permit
and prohibit certain software combinations. This would potentially have
a serious impact on interoperability. Then, software combinations could
become dangerous liaisons.



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