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Copyleft software is a way to develop code. It means that people are allowed to freely use and modify the source code of software as long as they preserve these same rights in the derivative works they make. However, there are common mistakes you could make when using copyleft software. You can avoid these if you understand and choose the correct copyleft licence for you in accordance with copyright law. Copyleft has a lot of advantages that can significantly benefit you. Although, if you make a crucial mistake when using copyleft software, you could be facing the consequences for a long time. This article will set out copyleft in regards to software and some common mistakes to avoid.

What is Copyright?

It is important to understand copyright law when trying to understand copyleft. Copyright is an automatic intellectual property right in New Zealand. This means that there is no registration needed. Instead, your work is protected automatically. Original work is protected under copyright law and must be under one of the following categories:

  • literary, dramatic, musical and artistic works;
  • the typographical layout of published editions;
  • sound recordings;
  • films; and
  • communication works.

If you have created work, you will have rights and protections. These are:

  • the right to copy and use your copyrighted work;
  • the right to stop others from copying or using your copyrighted work; and
  • legal protection.

The duration of these copyright protections will vary depending on what kind of work they protect. If you like, you can mark your copyrighted material with the © symbol.

Generally, the creator of the copyrighted work is the copyright owner. However, there are situations where another person can become the copyright owner. For example, if you are employed to create copyrighted material, then your employer will likely be the copyright owner. You can outline this in your employment contract.

You can also licence copyright rights to another person. A licence agreement is a tool that a copyright owner can use to share their copyrighted work without any risk of losing their ownership rights. Licence agreements are flexible to suit the needs of both parties. As a result, it is common for licence agreements to have varied terms and conditions.

What is Copyleft?

Copyleft is commonly referred to as the opposite of copyright. Copyleft material is free to be used by anyone without permission and has no rights or protections imposed over it. This means that the original material can be used freely, whatever is created from that remains free, and so on. Once established, copyleft overrides copyright.

Copyleft software refers to a source code that is free to be modified and used by others. The idea behind copyleft software is that free distribution of codes will bring about faster and more significant code development.

Copyleft promotes collaboration and includes some key features, including:

  • unrestricted access to the original work and any work produced after that;
  • giving all users equal access;
  • acknowledging each contribution to the original work and any work after that;
  • no threat of infringement from using the copyleft material; and
  • no threat of consequences if the copyleft material does not work.

Common Copyleft Software Mistakes

Being Unsure of the Copyright Owner

Only the copyright owner can enter into a copyleft licence. So even if you are the creator of the work, you cannot put the work under copyleft unless you are also the copyright owner.

Forgetting That Copyleft is Permanent

You cannot revoke copyleft licences. So, if you have already shared your free software under copyleft and seen vast growth and profit, you cannot take back your copyright rights and determine who can use and profit from it. Because of this, you must consider factors such as financial gain and your plans for the future before you use a copyleft licence.

Not Understanding Copyleft Licencing

There are a few different types of copyleft organisations that offer licences you can obtain for your work. Some of the two most common ones are:

  • GNU; and
  • Creative Commons.

These are recognised and international organisations that work to promote the free sharing of creative material. However, while each share this common goal, they offer differing copyleft licence structures. You must understand these before you enter into one. This is because copyleft licences are permanent, and once you have entered into one, copyleft owners must apply the same terms forever.

If we look first at GNU, they offer a copyleft licence called GPL, which is a general public licence. As the name suggests, GPL is very general and not created for any specific purpose. This can be beneficial to someone who does not feel their work needs a specific licence. However, this also has risks because of the lack of clarity.

Creative Commons provides a few different types of licences depending on the level of permissiveness you require. This can range from giving up all rights to the public domain to only allowing others to use your material for non-commercial use.

Key Takeaways

Copyleft is a way for you to share your material freely with other creative minds. When using copyleft software, you can avoid common mistakes by:

  • knowing the rightful copyright owner;
  • understanding the permanency of copyleft; and
  • understanding and choosing the correct copyleft licence for you.

If you need more information about copyleft, LegalVision’s New Zealand IP lawyers can help. Call 0800 005 570 or fill out the form on this page. 

Frequently Asked Questions 

What is copyleft software?

Copyleft software is software or code that is free for anyone to use.

If I have used copyleft software, do I have to share it with others?

Yes, copyleft licences continue with the software no matter how many times they are modified.

How long does a copyleft licence last?

As a rule, they last forever. However, this might differ depending on where you get the licence from.

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