http://www.limecanvas.com/

1) I am not a lawyer. I code stuff.

2) Please seek appropriate legal council if you are planning to distribute code under any license.

3) The following information has been well researched and is imparted here for the benefit of informational understanding on the subject.

i.e. don’t say “But Wil said it was OK” in any court room.

GNU General Public License, aka GNU GLP or simply just GPL

• Most widely used “free software license”

• Guarantees end users (individuals, orgs, companies)

– Freedom to use

– Freedom to study

– Freedom to share (copy)

– Freedom to modify

Common misconception is that all GPL software is free (as in cost).

“Free” is aligned with “freedom to” i.e. rights, not cost.

“Free as in free speech, not free beer”

Yes!

As long as the software retains its GPL license.

The GNU project itself..

"encourages people who redistribute free software to charge as much as they wish or can... You can charge nothing, a penny, a dollar, or a billion dollars. It's up to you, and the marketplace.“

This covers executable code (binaries) not source code.

If you are planning on selling a binary (runnable/working) copy of a GPL software program…

• You must also include its source code

• Or a formal written offer, valid for 3 years, to provide the source code or access to it, to whoever possesses the binary copy.

GPL is “Copyleft” software, a play on Copyright.

Uses the practice of copyright law to offer the right to

• Distribute copies

• Distribute modified versions

AND here’s the important part…

“requiring that the same rights be preserved in modified versions of the work”

Once GPL – forever GPL

You are free to do what you like with GPL software…

…as long as it stays under GPL license

• For personal use

• For private use

• For commercial use

• For whatever

Important to recognise that licences are legal copyright entities. They…

• Impose conditions on reuse

• Impose conditions on redistribution

• Impose conditions on attribution

– You may have the right to redistribute

– You may not claim that you are the original author

Copyright and licenses don’t regulate “identity”-related issues outside the source code. e.g.

• Company Names

• Logos

These are separate legal entities covered by Trademark law.

You obtain some of my GPL software.

Yes, you can sell the software and keep the money for yourself without giving any of it to me.

You cannot however,

• Say or imply that it is your original work

• Use my company name or logo on it

• Imply that we are partners, or that I am in any way responsible for support or refunds, in any situation

..do any of the things you shouldn’t do under GPL.

Doesn’t necessarily mean it’s an illegal act.

It means that those issues outside the scope of the software license and may be dealt with separately and/or legally.

e.g. Under the “Apache license”*, you must obtain their permission before using their trademarks and logos.

*Apache license is another type of “free software” license similar to GPL

Version 1 – 1989

• Freedom to share and modify. GNU project original.

Version 2 – 1991

• “Liberty or Death" clause. If anyone imposes restrictions on GPL. They can’t distribute under it.

Version 3 – 2007 (current)

• Addresses software patents, Digital Rights Management (DRM)and internationalisation.

Add two elements to each source file of your software

1. A copyright notice e.g. Copyright Lime Canvas Ltd.

2. a statement of copying permission, saying that the program is distributed under the terms of the GNU General Public License

For a single file program:

Copyright Lime Canvas Ltd.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

For a multi-file programs:

Copyright Lime Canvas Ltd.

This file is part of Pooky.

Pooky is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Pooky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Pooky. If not, see <http://www.gnu.org/licenses/>.

The WordPress “core”

• The WordPress “program” is licensed under GPL

• Includes many other external libraries which may hold their own GPL license

Themes & Plugins

• Considered separate entities (outside the core)

• These can be licensed under GPL

Themes

• In the style.css, root folder of the theme

• e.g. TwentyThirteen License: GNU General Public License v2 or later License URI: http://www.gnu.org/licenses/gpl-2.0.html

Plugins

• In the readme.txt (readme.md) and in the plugin bootstrap (PHP loader file). Comment at top of file.

• e.g. Akismet License: GPLv2 or later

Two sites caused a stir in GPL/Premium add-ons in 2013; WP Avengers and GPL Club.

Both took (bought) premium WooCommerce themes and plugins and offer them for lower prices than the original.

This is legal under GPL but is it ethical or moral to do so?

What does it mean for premium providers?

The positives

• Both offer commercial products at a lower price

• This is completely legal and encouraged under GPL Many have cited this a stealing code from hard working developers, however, it is all licensed under GPL so this is not correct.

• Good for those who don’t need support

• More people can afford to buy the software

• Both offer updates to newly released versions

Possible negatives

• GPL Club specifies that support is only provided by original product authors. This is possibly in violation with GPL and certainly not “in the spirit” of GPL.

• WP Avengers offer paid access to a forum for “premium support”.

• Support is always best handled by the program authors who maintain existing and release new versions.

There are many models for selling under GPL.

It is common now to pay for support and updates

How would the premium add-on market react if all GPL software was available for free (no cost)?

We can’t answer that question but perhaps somebody will write a presentation about it when it happens.

Visit gnu.org https://www.gnu.org/licenses/quick-guide-gplv3.html

[1] en.wikipedia.org

[1] xda-developers.com

[2] openclipart.org

[4] synopse.info

[6] zazzle.com.au

[26] gnu.org