1. THE GPL
WHAT IT MEANS (AND WHAT IT DOESN’T)
NANCY THANKI

3. WHAT IS THE GPL?
WHAT DOES IT COVER?

4. FREE SOFTWARE VS OPEN SOURCE
“ the differences . . . are small:
nearly all free software is open
source, and nearly all open source
software is free.”
- Free Software Foundation (FSF)

5. THE FREE SOFTWARE DEFINITION’S FOUR FREEDOMS
BY THE FREE SOFTWARE FOUNDATION’S DEFINITION,
FREE SOFTWARE GUARANTEES YOU:
0 The freedom to run the program, for any purpose.
1 The freedom to study how the program works, and
change it so it does your computing as you wish.
2 The freedom to redistribute copies so you can help your
neighbor.
3 The freedom to distribute copies of your modified
versions to others.

6. VARIETY OF FREE SOFTWARE LICENSES
COMMONLY USED
▸ Apache Software License
▸ MIT License
▸ WTFPL – Do what the f*ck you want to public license
▸ The GNU General Public License (GPL)
Note: Each license has its own terms and may, or may not, be
compatible with the GPL’s terms, due to a few stipulations
within the GPL. *

7. OFFICIAL
DEFINITION

8. Short for General Public License, the license that
accompanies some open source software that
details how the software and its accompany
source code can be freely copied, distributed
and modified. The most widespread use of GPL is
in reference to the GNU GPL, which is commonly
abbreviated simply as GPLwhen it is understood
that the term refers to the GNU GPL. One of the
basic tenets of the GPL is that anyone who
acquires the material must make it available to
anyone else under the same licensing
agreement.
- webopedia

9. - webopedia
▸ The GPL does not cover activities other than
the copying, distributing and modifying of the
source code.
▸ A GPL is also referred to as a copyleft, in
contrast to a copyright that identifies the
proprietary rights of material.

10. GNU IS NOT IN THE PUBLIC DOMAIN. EVERYONE WILL BE
PERMITTED TO MODIFY AND REDISTRIBUTE GNU, BUT NO
DISTRIBUTOR WILL BE ALLOWED TO RESTRICT ITS
FURTHER REDISTRIBUTION. THAT IS TO SAY, PROPRIETARY
MODIFICATIONS WILL NOT BE ALLOWED. I WANT TO MAKE
SURE THAT ALL VERSIONS OF GNU REMAIN FREE.
Richard Stallman, GNU Manifesto (1985)
COPYLEFT (Ɔ)

11. WHAT DOES THAT
MEAN?

12. TERMINOLOGY
COPYLEFT (Ɔ)
▸ a play on the word copyright
▸ the practice of offering people the right to freely distribute
copies and modified versions of a work
▸ the stipulation is that the same rights must be preserved in
derivative works down the line
▸ i.e. not only make your work free, but to ensure that any
modified versions will also be free.

13. LIBRE, NOT
GRATIS
Richard Stallman

14. FREE AS IN SPEECH, NOT AS IN BEER

15. TERMINOLOGY
SHARE-ALIKE
▸ the requirement that any freedom that is granted
regarding the original work must be granted on exactly
the same or compatible terms in any derived work
▸ implies that any copy left license is automatically a share-
alike license, but not the other way around (not all share-
alike licenses are copyleft)
Note: Check out the variety of Creative Commons licenses for examples of the variety
of share-alike licenses

16. =
FOUR FREEDOMS
GPL

17. THE FREE SOFTWARE DEFINITION’S FOUR FREEDOMS
BY THE FREE SOFTWARE FOUNDATION’S DEFINITION,
FREE SOFTWARE GUARANTEES YOU:
0 The freedom to run the program, for any purpose.
1 The freedom to study how the program works, and
change it so it does your computing as you wish.
2 The freedom to redistribute copies so you can help your
neighbor.
3 The freedom to distribute copies of your modified
versions to others.

18. GPL =
FOUR FREEDOMS
+ COPYLEFT

19. USING THE GNU GPL WILL REQUIRE THAT ALL THE
RELEASED IMPROVED VERSIONS BE FREE SOFTWARE.
THIS MEANS YOU CAN AVOID THE RISK OF HAVING TO
COMPETE WITH A PROPRIETARY MODIFIED VERSION
OF YOUR OWN WORK.
- “Why Use the GPL”
FREE SOFTWARE FOUNDATION’S TAKE ON THINGS

20. SO WHAT…?
▸ Free software is used in every
device, software, and site you
regularly use
▸ for example: WordPress (a Free
Software project) powers over 25%
of the web
▸ ecosystem of developers and
freelancers making livings off of
WP-related business

21. WORDPRESS

22. “ENSURE FREE
ACCESS, IN
PERPETUITY, TO THE
SOFTWARE PROJECTS
WE SUPPORT”
WordPress Foundation

23. THE GPLV2 (OR LATER) FROM THE FREE SOFTWARE FOUNDATION IS THE
LICENSE THAT THE WORDPRESS SOFTWARE IS UNDER.
VERSION 2, JUNE 1991
COPYRIGHT (C) 1989, 1991 FREE SOFTWARE FOUNDATION, INC.
51 FRANKLIN ST, FIFTH FLOOR, BOSTON, MA 02110, USA
GNU General Public License @ WordPress.org
GNU GENERAL PUBLIC LICENSE AKA GNU GPL / THE GPL

24. IMPACT GPL license family

25. THE REASONS FOR WORDPRESS RELEASING UNDER
THE GPL ARE BOTH PRACTICAL AND IDEALISTIC.
WORDPRESS WAS BORN OF THE VERY FREEDOM
MENTIONED EARLIER. THE PREDECESSOR TO THE
WORDPRESS PROJECT, B2/CAFELOG, WAS ALSO AN
OPEN SOURCE PROJECT.
License on the WordPress Codex
HISTORY

26. HOW DOES THE GPL
COMPARE TO OTHER
LICENSES?
MIT, Apache, GitHub, Flickr (Creative Commons)

28. DOES THE
VERSION MATTER?

29. FEBRUARY 25, 1989
VERSION 1
1. any vendor distributing binary files (executable, but not readable or
modifiable by humans) must also make the human-readable source
code available under the same licensing terms (Sections 3a and 3b)
2. modified versions, as a whole, has to be distributed under the terms
of GPLv1 (Sections 2b and 4)
▸ allowed GPL software to be combined with software that had
more permissive terms without changing its own terms
▸ disallowed combing with software distributed with more
restrictive licensing as that would conflict with #1

30. JUNE 1991
VERSION 2
▸ the developer may not distribute their work if a license
imposes restrictions that prevent distributing GPL software
in a way that disrespects other users’ freedom
▸ hopefully this makes it less tempting for companies to use
patent threats to require fees from free software
developers
▸ aka the “Liberty or Death” clause

31. The GPL in a small nutshell
YOU CAN COPY AND DISTRIBUTE THE PROGRAM, YOU
CAN CHARGE A FEE FOR TRANSFERRING THE PROGRAM
OR PROVIDING WARRANTY PROTECTION, AND YOU CAN
MODIFY THE PROGRAM AND DISTRIBUTE YOUR
RESULTING DERIVATIVE WORK. BUT, IF YOU DISTRIBUTE
YOUR DERIVATIVE WORK, YOU NEED TO LICENSE IT
UNDER THE GPL, OTHERWISE YOUR LICENSE TO USE THE
PROGRAM WILL TERMINATE (AND YOU’LL BE INFRINGING
COPYRIGHT IN THE PROGRAM).

32. JUNE 29, 2007
VERSION 3
▸ disallow hardware restrictions on software modification aka
“tivoization”
▸ addresses compatibility with other free software licenses
▸ strips Digital Rights Management (DRM) of its legal value, i.e.
people can break anything a court may recognize as DRM on a
GPL licensed software without breaking the DMCA
▸ prevent patent-related agreements, for example the Microsoft-
Novell patent agreement
▸ can only be combined with GPLv2 if it includes the “or any later
version” clause

33. PER SITE
PERSONAL SITE
BUSINESS SITES
the entire source code needs to
be made available to end users
if for sale or distribution
GPL software can be run for all purposes
including commercial purposes
even as a tool for creating proprietary software
charge a fee for copies or give them away
the software can be modified or
reused without releasing the
source code if it is being used
privately or internally (no sales or
distribution)

34. ONEYMONEYMONEYMONEYMONEYMONEYMONEYMONEYMONEYMONEYMONEYMONEYMONEY
IN PRACTICE
‣ premium WordPress plugin and theme developers usually
sell a license key providing access to support and
automatic upgrades
‣ without this license, the software should continue to work,
but you won’t benefit from updates (new features, bug
fixes, security hardening, etc) or support for questions or
issues

35. Q: If I modify the core WordPress software or a GPL theme/
plugin, do I have to release the source code of the modified
versions(s) to the public?
A: If you are using the modified version privately without
distribution, then you do not have to release the source code
of the modified version to the public.
However, “if you release the modified version to the public in
some way, the GPL requires you to make the modified source
code available to the program’s users, under the GPL.” -FSF

36. Q: Say I take a GPL theme/plugin from the WordPress theme
or plugin repository, or I purchase a GPL theme or plugin
from a commercial provider. Then I modify the theme or
plugin for my own purposes. Do I have to release my
modified version to others?
A: No, you are not obliged to release your modified version
to others.

37. Q: Can I sell the core WordPress software?
A: Yes. Doing so is consistent with the freedoms in the GPL.
However, trying to do so would be pointless and unlikely to
earn you any money, as everyone knows or could easily find
out that WordPress is freely available at wordpress.org.

38. Q: I’ve purchased a GPL theme(s)/plugin(s) from a commercial theme
or plugin provider. May I sell those themes or plugins from my own
website for my own benefit? What about publishing those themes or
plugins on my own website and give them away for free?
A: Yes, under the GPL, you may do either of these things (or both on
separate sites if you were so inclined).
Bear in mind that some in the WordPress community are likely to
frown on such activity and that you are unlikely to be able to provide
(or may not wish to provide) the support that the developers/owners
can provide.

39. Q: I take a GPL theme or plugin from the WordPress theme
or plugin repository, or I purchase a GPL theme or plugin
from a commercial provider, and then I modify the theme or
plugin for my own purposes. Do I have to release my
modified version to others?
A: No, you are not obliged to release your modified version
to others.

40. Q: I’m a theme/plugin developer. I’ve put huge effort into writing my theme/plugin
and I’m going to release it under the GPL but I want to make sure that everyone
who receives my theme or plugin, even if from someone else, is obliged to pay me
a licensing fee or notify me that they have it. Can I do that?
A: No.
The “GPL is a free software license, and therefore it permits people to use and even
redistribute the software without being required to pay anyone a fee for doing so.”
-FSF
Similarly, if someone receives a copy of GPL software, that person does not have to
inform the developer that s/he has it.
You are entitled to charge a fee for access to support and later versions, but this is
quite different to requiring recipients to pay a licensing fee for merely using the
software.

41. Q: I’m a commercial theme or plugin developer. I sell my
GPL theme or plugin online, behind a pay wall. People can
only access the theme or plugin files after paying my
prescribed fee. Does the GPL allow me to do this?
A: Yes.
You are entitled to charge a fee for distributing copies of
GPL’d software. Note, however, that anyone who obtains a
copy is entitled to release it to anyone else, with or without
charge; the GPL allows this to occur.

42. Q: I’m the same commercial theme or plugin developer
mentioned previously, selling my GPL theme or plugin online
behind a pay wall. As a commercial operator distributing a
GPL program, do I have to (for example, if someone asks)
make my theme or plugin available to a member of the
public for free?
A: No. However, as noted earlier, anyone who obtains a copy
is entitled to release it to anyone else, with or without
charge.

43. Q: I’m the same commercial theme or plugin developer
mentioned previously, selling my GPL theme or plugin online
behind a pay wall. As a commercial operator distributing a
GPL program, do I have to (for example, if someone asks)
make my theme or plugin available to a member of the
public for free?
A: No. However, as noted earlier, anyone who obtains a copy
is entitled to release it to anyone else, with or without
charge.

44. RESELLING
RESELLING COMMERCIAL PLUGINS AND THEMES - WPANDLEGALSTUFF
▸ comply with the GPL
▸ not infringe any trademark or other branding rights
▸ not pass of any non-existing relationship with the original
developer or business
▸ not breach any fair trading laws based on the location
▸ not infringe any copyright in non-code files

45. SECTION 2
GPL AND COMMERCIAL THEMES
‣ the intent is to control the distribution of derivative or collective works based on
the Program, not to “contest your rights to work written entirely by you”
‣ if identifiable sections of the modified work are not derived from the Program, and
can be reasonably considered independent and separate works in themselves,
then the GPL does not apply to them when distributed as separate works;
‣ however, 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 the
GPL; and
‣ “mere aggregation of another work not based on the Program with the Program (or
with a work based on the Program) on a volume of a storage or distribution
medium does not bring the other work under the scope of [the GPL]”.

46. WHY IN THE WORLD WOULD I RELEASE MY CREATIONS UNDER THE GPL?
FOSS AND THE
SMARTEST PERSON IN
THE ROOM*
* Clay Shirky’s talk on “Institutions vs Collaboration”

47. “NO MATTER WHO YOU
ARE, MOST OF THE
SMARTEST PEOPLE
WORK FOR SOMEONE
ELSE.”
Billy Joy

48. COSTS
MAINTAINING CLOSED SOFTWARE
▸ security vulnerabilities
▸ closed software, for example Facebook, Apple, etc
▸ hire the smartest people in the world to stay ahead of
the problems
▸ open source, for example Linux, WordPress, etc
▸ allow the software to evolve with community
contributions

49. GPL INFECTION

50. …A CANCER THAT ATTACHES
ITSELF IN AN INTELLECTUAL
PROPERTY SENSE TO EVERYTHING
IT TOUCHES…
Steve Ballmer, Microsoft CEO, 2001
REFERRING TO LINUX

51. THIS VIRAL ASPECT OF THE GPL
POSES A THREAT TO THE
INTELLECTUAL PROPERTY OF ANY
ORGANIZATION MAKING USE OF IT.
Craig Mundie, Microsoft Senior VP, 2001
REFERRING TO THE GPL

52. “GPL IGNORE”

53. CLOSED SOURCE
CONTENT

54. GPL IS A LEGAL COPYRIGHT THAT
PROVIDES USERS WITH THE LEGAL
RIGHTS (AND RESPONSIBILITIES) OF
COPYLEFT

55. CRITICISMS

56. WHAT ABOUT
SPLIT LICENSING?

57. THE THEMES PRESENTED, AND ANY THAT
ARE SUBSTANTIALLY SIMILAR, CONTAIN
ELEMENTS THAT ARE DERIVATIVE WORKS
OF THE WORDPRESS SOFTWARE AS WELL
AS ELEMENTS THAT ARE POTENTIALLY
SEPARATE WORKS. SPECIFICALLY, THE CSS
FILES AND MATERIAL CONTAINED IN THE
IMAGES DIRECTORY OF THE “DEFAULT”
THEME ARE WORKS SEPARATE FROM THE
WORDPRESS CODE. ON THE OTHER HAND,
THE PHP AND HTML CODE THAT IS
INTERMINGLED WITH AND OPERATED ON
BY PHP THE CODE DERIVES FROM THE
WORDPRESS CODE.
aka “PHP in WordPress
themes must be GPL,
artwork and CSS may be
but are not required.”
SOFTWARE FREEDOM LAW CENTER, 2009

58. TEXT
FINAL PRODUCTS
▸ Do WordPress themes or plugins have to be GPL?
▸ What if you write a Google Maps app that interacts with
the API and links users to their Fitbit data? Does the final
product need to also be GPL?
▸ And if you sell it, can it be sold as non-GPL?

59. GOOD IDEAS AREN’T THE SOLE PROVINCE
OF GROUPS OF PEOPLE BEHIND HIGH
WALLS, AND SOFTWARE SHOULDN’T BE
EITHER.
Matt Mullenweg
WHAT IS OPEN SOURCE?

60. FREE SOFTWARE IS A POLITICAL
MOVEMENT; OPEN SOURCE IS A
DEVELOPMENT MODEL.
Richard Stallman
TEXT

61. ALL THE LINKS :)
SOURCES
▸ http://www.webopedia.com/TERM/G/GPL.html
▸ http://www.gnu.org/licenses/gpl-faq.html
▸ http://www.dmoz.org/Computers/Open_Source/Licenses/
▸ https://opensource.org/licenses/gpl-license.php
▸ https://en.wikipedia.org/wiki/GNU_General_Public_License
▸ https://en.wikipedia.org/wiki/Copyleft
▸ http://wpandlegalstuff.com/understanding-gpl-licensing-wordpress/
▸ https://wordpress.org/about/gpl/
▸ https://ivycat.com/a-newbies-guide-to-the-gpl-and-wordpress-licensing/
▸ http://wpandlegalstuff.com/understanding-gpl-licensing-wordpress/
▸ http://wpandlegalstuff.com/readers-ask-about-reselling-commercial-plugins/
▸ http://wpandlegalstuff.com/a-reader-asks-selling-themeforest-themes-outside-of-themeforest/
▸ http://wpandlegalstuff.com/wordpress-themes-gpl-conundrum-derivative-works/
▸ https://enriquesthoughts.wordpress.com/2014/01/05/wordpress-is-gpl-must-your-plugin-be-as-well/
▸ http://www.wpmayor.com/wordpress-gpl-abuse/
▸ http://themeforest.net/collections/3516382-100-gpl-wordpress-themes
▸ http://wordpress.tv/2009/10/13/matt-mullenweg-wordpress-gpl/
▸ http://pointlessness.arc-nova.org/2006/december/gpl-misconceptions.php
▸ http://www.groklaw.net/article.php?story=20031214210634851
▸ https://michaeltorbert.com/wordpress-plugin-theme-gpl/
▸ https://ma.tt/2014/01/four-freedoms/
▸ http://www.newyorker.com/business/currency/the-gnu-manifesto-turns-thirty