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Roger Clarke's 'Open Source Licensing'

Open Source Licensing

Roger Clarke

Chair, AEShareNet Limited

Principal, Xamax Consultancy Pty Ltd, Canberra

Visiting Professor, Baker & McKenzie Cyberspace Law & Policy Centre, University of N.S.W.

Visiting Fellow, Department of Computer Science, Australian National University

This is a companion resource to papers on The Spectrum of Content Licensing and Open Source and Open Content as Models for e-Business

Version of 25 September 2003

© Xamax Consultancy Pty Ltd, 2003

Available under an AEShareNet Free for Education licence

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This paper provides background information on the dissemination of software by means of open source licences.


1. Closed, 'Lock in' or 'Proprietary' Software

'Open source software' is distinguished from software that is only available under highly restrictive copyright licence terms. Very commonly, owners of the copyright in software use copyright law to prevent their software from being copied, adapted, or re-distributed (either in the original or an adapted form). If those actions are permitted at all, then they are likely to be subject to tight limitations and high fees.

Such an approach is sometimes referred to as 'proprietary', but that is not an appropriate term. The term 'closed' is better. Another descriptor that has been proposed is 'lock in' software (Scott 2003).

Whatever the approach many be called, it represents the active exercise of copyright law by the owner in an endeavour to maximise financial returns, and as a direct weapon against both competitors and customers.

2. Public Domain Software

The owner of 'open source software', on the other hand, seeks to ensure that software is readily available to anyone.

The obvious thing to do would be to release it into the public domain. Unfortunately, this is not an effective way to achieve the aim. One reason is that copyright law enables other people to use the public domain materials to generate copyright-protected works, even if, in doing so, they make no significant intellectual contribution. Another reason is that the executable code might be readily available, but the source-code might not be.

3. Open Source Software

The open source software approach works within conventional copyright law in order to achieve openness. The owner asserts ownership of the software, but then makes it available under relatively very liberal licence terms.

The motivation for openness is that software should not be thought of as being a fixed product. It needs to evolve. The only efficient way for evolution to occur is by enabling copies to mutate. That requires free availability of both the executable code, and of the source-code from which the executable is derived. Open source software is readily subjected to peer review, bugs and insecurities are more likely to be discovered, and cumulative progress is more likely.

A key difference between the two is that 'open source' software can be used to create 'closed source', proprietary software; whereas the 'free software' philosophy precludes that. The Free Software Foundation provides an explanation of the distinctions between the two. The Open Source movement distances itself from Stallman, claiming to be "a pitch for 'free software' on solid pragmatic grounds rather than ideological tub-thumping".

It is important to appreciate the concepts of 'free' and 'open':

* 'open' means 'openly accessible'; and

* 'free' does not mean 'gratis', but rather refers to 'freedom to exploit'.

An open source software licence might be gratis, but that it may require the payment of a fee, and possibly a high fee. In any case, services associated with open source software very probably do cost money, e.g. the media on which it is stored, installation advice, customisation, and maintenance services.

4. Open Source Software Licence Terms

Features of open source software licences fall under the following broad categories. Note that some are absolute requirements, but many are implemented in a variety of ways.

It is fundamental that there be ready availability of:

The licences needs to provide a number of permissions, in particular:

The licence may then impose a number of constraints, in particular:

Software may be available under an open source licence if used for some purposes, or by some categories of person; but not otherwise. For example, not-for-profit use may be permitted, but not for-profit use. (Differential licences are, however, a subject of some debate).


The following are resources relevant to 'open source':


Gabriel R.P. & Goldman R. (2002) 'Open Source: Beyond the Fairytales' August 2003, at

Green E.L. (2002) 'Economics of Open Source Software', rev. December 2002, at

Iannacci F. (2002) 'The Economics of Open-Source Networks', October 2002, at

Lerner J. & Tirole J. (2000) 'The Simple Economics of Open Source' National Bureau of Economic Research, Boston Mass., Working Paper 7600, at

Pal N. & Madanmohan T.R. (2001) 'Competing on Open Source: Strategies and Practise' January 2002, at

Raymond E.S. (1998) 'The Cathedral and the Bazaar' First Monday 3,3 (March 1998), at

Scott B. (2003) 'Lock in Software', March 2003, at

Stutz M. (2000?) 'Copyleft and the Information Renaissance', at

Stutz M. (2000) 'Open Source Beyond Software' O'Reilly Network, August 2000, at

Examples of Software Available under Open Source Licences

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Created: 20 June 2003 - Last Amended: 25 September 2003 by Roger Clarke - Site Last Verified: 15 February 2009
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