+ FSF: Understanding the purpose and intent of the GPL.

+ Conservancy & FSF:

    + both enforce the GPL.

    + if your client violates, you will hear from one of us.

+ Such access to drafters, interpreters, enforcers is highly unique.

+ Someday, we may (or already have) sit across the table from you.

+ Our transparency does make your job easier. 

# The Mindset of GPL

+ GPL protects software freedom.

+ Ultimate goal: make sure every user has the four freedoms.

     + Freedom to run the software.

     + Freedom to study and modify the software.

     + Freedom to share the software.

     + Freedom to distribute modified versions.

+ Every clause in GPL was designed to uphold one of these freedoms.

     + Or, it's a compromise of drafting in adoption vs. freedom debate.

# Using Copyright

+ GPL is primarily a copyright license.

      + Software is copyrighted.

      + License grants key freedoms.

      + Requirement prohibit activities that take away freedoms.

+ General concept: copyleft.

+ Specific implementation: GPL.

<hr/>

<span class="fitonslide">

> Copyright protection subsists … original works of authorship fixed in any tangible medium of expression …  from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device.

<p align=right>

 &mdash; <a href="http://www.law.cornell.edu/uscode/text/17/102">17 USC &sect;102</a>

</p>

</span>

# Conditional Permissions

+ A copyleft license grants copyright permissions, conditionally.

+ Think of the phrase: “provided that”

+ “provided that”: appears (in some form) only

+ 4 times in GPLv2

+ 9 times in GPLv3.

# Compare To Proprietary Licenses

+ Yes, the GPL has its requirements.

+ But *none* of these activities are ever permitted under proprietary

  licenses.

+ If you don't like what the GPL requires you to do, then just tell your

  client to use the proprietary software instead.

+ That way, they know the answer to every question is “no&;rdquo,

+ rather than: “yes, but only as long as you …”

# The Technical Gap

+ Understanding GPL well requires a some software expertise & legal

  expertise.

+ You don't have to be a professional on either side to grok it.

     + but you're best off if you're a professional in one & an amateur

       in the other. 

+ Most important technical concepts you need:

     + source code, binaries, methods of distribution.

# Considering Sections of the GPL

+ With the remaining time …

     + in interest of the experts in the audience …

     + let's dig into a few specific sections.

+ GPL ♥ 17 USC§106(2) & 17 USC§106(3)

+ Modification and distribution.

# Why Permission to Modify?

+ Your new copyrights are your copyrights:

     + you are affixing it in a tangible medium.

+ Exclusive right of copyright holders:

     + Control on “preparation of derivative works”

     + Distribution of the work.

     + Note the combination of these.

+ Again, see 17 USC§106

+ N.B.: “derivative works” is USA-centric, modify is more international)

# Modification As a Center Provision

+ GPL's primary copyright hook is copyright controls on the right to modify.

+ GPL's central tenant:

+ You can make a modified version of various types privately as much as you'd like.

+ When you distribute that modified version, you have requirements to meet.

+ Technological considerations dictate necessity of more complex rules for

certain types of modifications.

# GPLv2 § 2(a-b)

<span class="fitonslide">

<p>[GPLv2&sect;]2. You may modify your copy or copies of the Program or any

portion of it, thus forming a work based on the Program, and copy and

distribute such modifications or work under the terms of Section 1 above,

provided that you also meet all of these conditions:

<br/>

<br/>

a) You must cause the modified files to carry prominent notices stating

that you changed the files and the date of any change.

<br/>

<br/>

b) You must cause any work that you distribute or publish, that in

whole or in part contains or is derived from the Program or any

part thereof, to be licensed as a whole at no charge to all third

parties under the terms of this License.

</p>

</span>

# GPLv3§5(a-c)

<span class="fitonslide">

<p>

You may convey a work based on the Program, or the modifications to

produce it from the Program, in the form of source code under the

terms of section 4, provided that you also meet all of these conditions:

<br/>

<br/>

a) The work must carry prominent notices stating that you modified it, and

giving a relevant date.

<br/>

<br/>

b) The work must carry prominent notices stating that it is released under

this License and any conditions added under section 7.  This requirement

modifies the requirement in section 4 to "keep intact all notices".

<br/>

<br/>

c) You must license the entire work, as a whole, under this License to anyone

who comes into possession of a copy.  This License will therefore apply,

along with any applicable section 7 additional terms, to the whole of the

work, and all its parts, regardless of how they are packaged.  This License

gives no permission to license the work in any other way, but it does not

invalidate such permission if you have separately received it.

</p>

</span>

# GPLv2§2¶ ante-penultimate & penultimate

<span class="fitonslide">

<p>

These requirements apply to the modified work as a whole.  If

identifiable sections of that work are not derived from the Program,

and can be reasonably considered independent and separate works in

themselves, then this License, and its terms, do not apply to those

sections when you distribute them as separate works.  But when you

distribute the same sections as part of a whole which is a work based

on the Program, the distribution of the whole must be on the terms of

this License, whose permissions for other licensees extend to the

entire whole, and thus to each and every part regardless of who wrote it.

<br/>

<br/>

Thus, it is not the intent of this section to claim rights or contest

your rights to work written entirely by you; rather, the intent is to

exercise the right to control the distribution of derivative or

collective works based on the Program.

</p>

</span>