Open-Source Software, Copyleft or Copyright

Open-source software has been the subject of international debate since Linus Torvalds developed Linux as a hobby in the early 1990’s.

With the acceleration of digital transformation, the use of open-source code has expanded thanks to the speed, flexibility, extensibility, and quality that is now offered by application development teams. This, however, has created new commercial and legal risks.

What is open-source software

Open-source software (OSS) is non-proprietary software that allows anyone to modify, distribute, enhance, or simply view its source code.

Open-source licensing

Although OSS is generally “free to use”, the actual use is permitted under licence by the OSS’ owner.

OSS licences will comply with the “Open-Source Definition” which requires OSS to be freely used, modified, and shared by the public. The following are some examples of OSI approved licenses:[1]

  • Apache License 2.0
  • BSD 3-Clause “New” or “Revised” license
  • GNU General Public License (GPL)
  • GNU Library or “Lesser” General Public License (LGPL)
  • MIT License
  • Mozilla Public License 2.0
  • Common Development and Distribution License
  • Eclipse Public License version 2.0

The author (or owner) of the OSS maintains rights under copyright law. However, the terms of the OSS licence will permit free use of the OSS.  


“Copyleft” is a concept where the distribution of OSS by a party other than the copyright owner must replicate those terms contained within the original OSS licence. That is, if the OSS is free for the public to use, then any redistribution by the public of that OSS (albeit modified) must also be open to the public. 

For example, where a developer creates software and then releases it under the GNU General Public License (GNU GPL), if someone else then modifies that software and distributes same, the modified version must also be licensed under the original GNU GPL.[2]

Copyleft imposes a limitation on the licensee, requiring that any adaptations or modified versions of the OSS are also released under an OSS licence.[3] This ensures the ongoing integrity of OSS, being the open and free use of software for altruistic purposes.

Not all OSS licenses constitute “copyleft”, such as:

  • permissive OSS or BSD-style licenses which are non-copyleft licenses, and do not place many restrictions on later development or modification of the original software; and
  • weak copyleft which can allow users to make modifications and keep them private or distribute them under a different license.

Key legal issues in dealing with OSS

Under the Copyright Act 1968 (Cth), copyright subsists in the source and object code of a computer program. Generally, copyright will vest in the author of the code (although code developed by an employee may vest in their employer). A person will infringe copyright if it deals with proprietary software in a particular way. However, if that person can prove that they did so under permission (or licence) of the owner, then there will be no infringement. Accordingly, it is vital that you consider the precise terms of any OSS licence prior to use, to ensure you are not acting beyond the scope of that licence. 

Furthermore, there is a danger in combining your own proprietary software with OSS, and then distributing this under the same OSS licence arrangement. Such conduct can lead to the loss of valuable intellectual property, given the requirement to distribute the software on the same terms as those set out in the relevant OSS licence.

Lavan Comment

When deciding upon use of OSS, there are a few basic questions you should ask:

  • How am I permitted to use and redistribute any modified versions of the OSS?
  • Is there a risk that I will lose valuable intellectual property by using and distributing OSS?

If you require any specific advice with respect to OSS, do not hesitate to contact Andrew Sutton or Iain Freeman.


[1] ‘Open Source Initiative’ (Web Page) <>.

[2] ‘GNU Operating System’ (Web Page) <>

[3] Mathew Baldwin (n 3).

Disclaimer – the information contained in this publication does not constitute legal advice and should not be relied upon as such. You should seek legal advice in relation to any particular matter you may have before relying or acting on this information. The Lavan team are here to assist.