Tuesday, March 6, 2012

How to license your free software with GNU GPL v3

As you all know a software license is something that tells the users what they can or cannot do with that especific software and it's also a way of giving some credit to the author for his software.

There are several types of licenses:

- Perpetual license
- Subscription license
- Freeware license
- Shareware license
- OEM (original equipment manufacturer)
- Educational or Academic Software
- Not for Resale (NFR) Software License
- And more...

This post is specifically about Freeware Licences and specially about Open Source because, as you already know, inside free software applications we have some that are open source and others that are closed source.

So let's see a little bit more about free and open source software (quoting Wikipedia.org):
A primary consequence of the free software form of licensing is that acceptance of the license is essentially optional — the end-user may use, study, and privately modify the software without accepting the license. However, if the user wishes to exercise the right of redistributing the software, then the end-user must accept, and be bound by, the software license.
Free and open-source licenses generally fall under two categories: Those with the aim to have minimal requirements about how the software can be redistributed (permissive licenses), and those that aim to preserve the freedoms that is given to the users by ensuring that all subsequent users recives those rights (copyleft Licenses).
An example of a copyleft free software license is the GNU General Public License (GPL). This license is aimed at giving all user unlimited freedom to use, study, and privately modify the software, and if the user adheres to the terms and conditions of GPL, freedom to redistribute the software or any modifications to it. For instance, any modifications made and redistributed by the end-user must include the source code for these, and the license of any derivative work must not put any additional restrictions beyond what GPL allows.[1]
Examples of permissive free software licenses are the BSD license and the MIT license, which give unlimited permission to use, study, and privately modify the software, and includes only minimal requirements on redistribution. This gives a user the permission to take the code and use it as part of closed-source software or software released under a proprietary software license.

free and open source license GPL

One of the most known and used license for this type of software is the GNU GPL(General Public License) that is now on version 3. The bases of this license, quoting gnu.org, are:

The Foundations of the GPL

Nobody should be restricted by the software they use. There are four freedoms that every user should have:
  • the freedom to use the software for any purpose,
  • the freedom to change the software to suit your needs,
  • the freedom to share the software with your friends and neighbors, and
  • the freedom to share the changes you make.
When a program offers users all of these freedoms, we call it free software.
Developers who write software can release it under the terms of the GNU GPL. When they do, it will be free software and stay free software, no matter who changes or distributes the program. We call this copyleft: the software is copyrighted, but instead of using those rights to restrict users like proprietary software does, we use them to ensure that every user has freedom.
So if you developed a software and you are thinking about distributing it as a free software, i created a little video explaning what you need to do to license your software with GNU GPL v3. I am not an expert on this but i have already done this and i am just trying to share my experience.

Video turorial:

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