Copyleft/guide Changeset - d5864804ba05

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@@ -1608,20 +1608,20 @@ electronic file storage.

Therefore, for GPL'd software to be useful, the GPL, since it governs the

rules for creation of derivative works, must grant permission for the

generation of binaries. Furthermore, notwithstanding the relative

generation of binaries.  Furthermore, notwithstanding the relative

popularity of source-based GNU/Linux distributions like Gentoo, users find

it extremely convenient to receive distribution of binary software. Such

it extremely convenient to receive distribution of binary software.  Such

distribution is the redistribution of derivative works of the software's

source code. GPLv2~\S3 addresses the matter of creation and distribution of

source code.  GPLv2~\S3 addresses the matter of creation and distribution of

binary versions.

Under GPLv2~\S3, binary versions may be created and distributed under the

terms of GPLv2~\S1--2, so all the material previously discussed applies

here. However, GPLv2~\S3 must go a bit further. Access to the software's

here.  However, GPLv2~\S3 must go a bit further.  Access to the software's

source code is an incontestable prerequisite for the exercise of the

fundamental freedoms to modify and improve the software. Making even

fundamental freedoms to modify and improve the software.  Making even

the most trivial changes to a software program at the binary level is

effectively impossible. GPLv2~\S3 must ensure that the binaries are never

effectively impossible.  GPLv2~\S3 must ensure that the binaries are never

distributed without the source code, so that these freedoms are passed

through the distribution chain.

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@@ -1630,7 +1630,7 @@ distribution of source code along with binaries. The most common and the

least complicated is the option given under GPLv2~\S3(a).

GPLv2~\S3(a) offers the option to directly accompany the source code alongside

the distribution of the binaries. This is by far the most convenient

the distribution of the binaries.  This is by far the most convenient

option for most distributors, because it means that the source-code

provision obligations are fully completed at the time of binary

distribution (more on that later).

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@@ -1638,59 +1638,57 @@ distribution (more on that later).

Under GPLv2~\S3(a), the source code provided must be the ``corresponding source

code.''  Here ``corresponding'' primarily means that the source code

provided must be that code used to produce the binaries being distributed.

That source code must also be ``complete.''  A later paragraph of GPLv2~\S3

explains in detail what is meant by ``complete.''  In essence, it is all

That source code must also be ``complete''.   GPLv2~\S3's penultimate paragraph

explains in detail what is meant by ``complete''.  In essence, it is all

the material that a programmer of average skill would need to actually use

the source code to produce the binaries she has received. Complete source

the source code to produce the binaries she has received.  Complete source

is required so that, if the licensee chooses, she should be able to

exercise her freedoms to modify and redistribute changes. Without the

exercise her freedoms to modify and redistribute changes.  Without the

complete source, it would not be possible to make changes that were

actually directly derived from the version received.

Furthermore, GPLv2~\S3 is defending against a tactic that has in fact been

seen in FSF's GPL enforcement. Under GPL, if you pay a high price for

seen in GPL enforcement.  Under GPL, if you pay a high price for

a copy of GPL'd binaries (which comes with corresponding source, of

course), you have the freedom to redistribute that work at any fee you

choose, or not at all. Sometimes, companies attempt a GPL-violating

choose, or not at all.  Sometimes, companies attempt a GPL-violating

cozenage whereby they produce very specialized binaries (perhaps for

an obscure architecture). They then give source code that does

an obscure architecture).  They then give source code that does

correspond, but withhold the ``incantations'' and build plans they

used to make that source compile into the specialized binaries.

Therefore, GPLv2~\S3 requires that the source code include ``meta-material'' like

scripts, interface definitions, and other material that is used to

``control compilation and installation'' of the binaries. In this

``control compilation and installation'' of the binaries.  In this

manner, those further down the distribution chain are assured that

they have the unabated freedom to build their own derivative works

from the sources provided.

FSF (as authors of GPL) realizes that software distribution comes in many

forms. Embedded manufacturers, for example, have the freedom to put

GPL'd software into their PDAs with very tight memory and space

constraints. In such cases, putting the source right alongside the

binaries on the machine itself might not be an option. While it is

Software distribution comes in many

forms.  Embedded manufacturers, for example, have the freedom to put

GPL'd software into mobile devices with very tight memory and space

constraints.  In such cases, putting the source right alongside the

binaries on the machine itself might not be an option.  While it is

recommended that this be the default way that people comply with GPL, the

GPL does provide options when such distribution is infeasible.

GPLv2~\S3, therefore, allows source code to be provided on any physical

``medium customarily used for software interchange.''  By design, this

phrase covers a broad spectrum. At best, FSF can viably release a new GPL

every ten years or so. Thus, phrases like this must be adaptive to

changes in the technology. When GPL version 2 was first published in June

phrase covers a broad spectrum --- the phrase seeks to pre-adapt to

changes in  technology.  When GPLv22 was first published in June

1991, distribution on magnetic tape was still common, and CD was

relatively new. Today, CD is the default, and for larger systems DVD-R is

gaining adoption. This language must adapt with changing technology.

relatively new.  By 2002, CD is the default.  By 2007, DVD's were the

default.  Now, it's common to give software on USB drives and SD card.  This

language in the license must adapt with changing technology.

Meanwhile, the binding created by the word ``customarily'' is key. Many

Meanwhile, the binding created by the word ``customarily'' is key.  Many

incorrectly believe that distributing binary on CD and source on the

Internet is acceptable. In the corporate world, it is indeed customary to

simply download CDs worth of data over a T1 or email large file

attachments. However, even today in the USA, many computer users with

CD-ROM drives are not connected to the Internet, and most people connected

to the Internet are connected via a 56K dial-up connection. Downloading

CDs full of data is not customary for them in the least. In some cities

Internet is acceptable.  In the corporate world in industrialized countries, it is indeed customary to

simply download a CDs' worth of data quickly.  However, even today in the USA, many computer users are not connected to the Internet, and most people connected

to the Internet still have limited download speeds.  Downloading

CDs full of data is not customary for them in the least.  In some cities

in Africa, computers are becoming more common, but Internet connectivity

is still available only at a few centralized locations. Thus, the

``customs'' here must be normalized for a worldwide userbase. Simply

is still available only at a few centralized locations.  Thus, the

``customs'' here are normalized for a worldwide userbase.  Simply

providing source on the Internet --- while it is a kind, friendly and

useful thing to do --- is not usually sufficient.

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@@ -1703,77 +1701,76 @@ sufficient to comply with GPLv2~\S3.

\medskip

As is shown above, Under GPLv2~\S3(a), embedded manufacturers can put the

binaries on the device and ship the source code along on a CD\@. However,

sometimes this turns out to be too costly. Including a CD with every

binaries on the device and ship the source code along on a CD\@.  However,

sometimes this turns out to be too costly.  Including a CD with every

device could prove too costly, and may practically (although not legally)

prohibit using GPL'd software. For this situation and others like it, \S

3(b) is available.

prohibit using GPL'd software. For this situation and others like it, GPlv2\S~3(b) is available.

GPLv2~\S3(b) allows a distributor of binaries to instead provide a written

offer for source code alongside those binaries. This is useful in two

specific ways. First, it may turn out that most users do not request the

offer for source code alongside those binaries.  This is useful in two

specific ways.  First, it may turn out that most users do not request the

source, and thus the cost of producing the CDs is saved --- a financial

and environmental windfall. In addition, along with a GPLv2~\S3(b) compliant

and environmental windfall.  In addition, along with a GPLv2~\S3(b) compliant

offer for source, a binary distributor might choose to \emph{also} give a

URL for source code. Many who would otherwise need a CD with source might

URL for source code.  Many who would otherwise need a CD with source might

turn out to have those coveted high bandwidth connections, and are able to

download the source instead --- again yielding environmental and financial

windfalls.

However, note that regardless of how many users prefer to get the

source online, GPLv2~\S3(b) does place lasting long-term obligations on the

binary distributor. The binary distributor must be prepared to honor

binary distributor.  The binary distributor must be prepared to honor

that offer for source for three years and ship it out (just as they

would have had to do under GPLv2~\S3(a)) at a moment's notice when they

receive such a request. There is real organizational cost here:

receive such a request.  There is real organizational cost here:

support engineers must be trained how to route source requests, and

source CD images for every release version for the last three years

must be kept on hand to burn such CDs quickly. The requests might not

even come from actual customers; the offer for source must be valid

for ``any third party.''

for ``any third party''.

That phrase is another place where some get confused --- thinking again

that full public distribution of source is required. The offer for source

that full public distribution of source is required.  The offer for source

must be valid for ``any third party'' because of the freedoms of

redistribution granted by GPLv2~\S\S1--2. A company may ship a binary image

and an offer for source to only one customer. However, under GPL, that

redistribution granted by GPLv2~\S\S1--2.  A company may ship a binary image

and an offer for source to only one customer.  However, under GPL, that

customer has the right to redistribute that software to the world if she

likes. When she does, that customer has an obligation to make sure that

likes.  When she does, that customer has an obligation to make sure that

those who receive the software from her can exercise their freedoms under

GPL --- including the freedom to modify, rebuild, and redistribute the

source code.

GPLv2~\S3(c) is created to save her some trouble, because by itself GPLv2~\S3(b)

would unfairly favor large companies. GPLv2~\S3(b) allows the

would unfairly favor large companies.  GPLv2~\S3(b) allows the

separation of the binary software from the key tool that people can use

to exercise their freedom. The GPL permits this separation because it is

good for redistributors, and those users who turn out not to need the

source. However, to ensure equal rights for all software users, anyone

source.  However, to ensure equal rights for all software users, anyone

along the distribution chain must have the right to get the source and

exercise those freedoms that require it.

Meanwhile, GPLv2~\S3(b)'s compromise primarily benefits companies who

distribute binary software commercially. Without GPLv2~\S3(c), that benefit

distribute binary software commercially.  Without GPLv2~\S3(c), that benefit

would be at the detriment of the companies' customers; the burden of

source code provision would be unfairly shifted to the companies'

customers. A customer, who had received binaries with a GPLv2~\S3(b)-compliant

customers.  A customer, who had received binaries with a GPLv2~\S3(b)-compliant

offer, would be required under GPLv2 (sans GPLv2~\S3(c)) to acquire the source,

merely to give a copy of the software to a friend who needed it. GPLv2~\S3(c)

merely to give a copy of the software to a friend who needed it.  GPLv2~\S3(c)

reshifts this burden to entity who benefits from GPLv2~\S3(b).

GPLv2~\S3(c) allows those who undertake \emph{noncommercial} distribution to

simply pass along a GPLv2~\S3(b)-compliant source code offer. The customer who

simply pass along a GPLv2~\S3(b)-compliant source code offer.  The customer who

wishes to give a copy to her friend can now do so without provisioning the

source, as long as she gives that offer to her friend. By contrast, if

source, as long as she gives that offer to her friend.  By contrast, if

she wanted to go into business for herself selling CDs of that software,

she would have to acquire the source and either comply via GPLv2~\S3(a), or

write her own GPLv2~\S3(b)-compliant source offer.

This process is precisely the reason why a GPLv2~\S3(b) source offer must be

valid for all third parties. At the time the offer is made, there is no

valid for all third parties.  At the time the offer is made, there is no

way of knowing who might end up noncommercially receiving a copy of the

software. Companies who choose to comply via GPLv2~\S3(b) must thus be

prepared to honor all incoming source code requests. For this and the

software.  Companies who choose to comply via GPLv2~\S3(b) must thus be

prepared to honor all incoming source code requests.  For this and the

many other additional necessary complications under GPLv2~\S\S3(b--c), it is

only rarely a better option than complying via GPLv2~\S3(a).