% Considering Key Sections of the GPL

% Tuesday 9 May 2017

# 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.

# Considering Sections of the GPL

+ GPL ♥ 17 USC§106(2) & 17 USC§106(3)

+ GPL hinges on 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¶ penultimates