Recently the University of Göteborg held an online course in the theory and philosophy of free software and open source. During this course a lively discussion on terminology took place, in particular the concept of freedom was discussed. Without arriving at particular conclusions the posts included views in part on the lack of user awareness on what was property within the computer, on the difference between free, gratis, and libre in different languages and cultures and the need for both a common terminology and infrastructure. This paper is not an attempt to resolve these issues but to bring these questions to the attention of a wider audience in the hope that the discussion will continue.
To most outsiders the ethics of software is not something usually considered. To most proficient computer users with a passing interest in this question the ethics of software is recognised as one of the fundamental questions in the digital rights area. To most of the latter, terms such as free software, open source, and their derivatives (FLOSS, FOSS, Software Freedom) are interchangeable. Choosing one over the other is a matter of taste rather than politics. However, to most insiders the question is not one of taste. There is a fundamental difference between the two areas even if they share a similar root. Free software is not the same as open source. The two groups differ in their fundamental philosophical approach to software and its importance to society as a whole. This paper examines the two groups’ differing philosophies and explores how their actions have affected software development, access to fundamental software infrastructure, and the development of the concept of freedom.
The importance of free software
The freedom debate
Negotiating freedom & property
The importance of free software
Writing about the importance of software is difficult without resorting to what seems to be empty hyperbole. However it is important to point out that software is rapidly becoming one of the most fundamental building blocks of human interaction and activity. Authors such as Negroponte (1996), Mitchell (1996), Castells (1996), and Balkin (1998) have tried to help us understand the way in which software is changing most aspects of our lives. Despite the work these authors there is a common misconception that software is a complex component which in some sense "lives" within computer hardware. By confining software to the inner workings of the computer most nontechnical software users are unaware of the extent to which software permeates their lives.
Moglen (1999) writes about computers being under our social skin but this seems to imply that there are computers everywhere. To most people the computer is still a very specific artefact which only affects their lives in specific, controllable situations. Talking less about the computers and more about software may help bring about an understanding of the omnipresence of software. Also like most other things that surround us this software belongs to someone. The software that fills our homes and our lives is, in almost all cases, the property of someone else and therefore we are dependent upon the property of others for our everyday lives to a much greater extent that we may previously have imagined.
It was in part to counteract this that Richard Stallman wrote his original announcement for the GNU project in 1983. He wrote "Starting this Thanksgiving I am going to write a complete Unixcompatible software system called GNU (for Gnu’s Not Unix), and give it away free to everyone who can use it" . In 1985 Stallman launched the Free Software Foundation (FSF), an organisation whose goals it is to promote the computer users’ right to use, study, copy, modify, and redistribute computer programs.
The term "free software" includes a philosophy, an understanding that software is an important building block in the information society and that the control of this infrastructure needs to remains accessible to all. This egalitarian principle demands that software remain outside the control of those who would limit its usage and only provide this necessary infrastructure at a price. "Free software" refers not to price but to freedom and it is a deliberately confrontational term (Raymond, 1999), an attitude designed to provoke actors with commercial interests in proprietary software.
Stallman was to become the ideological father and leader of the free software movement and through this, one of the fundamental ideologists for open source. His views on software were dominant during 19831996, after which the focus on ideologicallycorrect software creation shifted to creating good software (Williams, 2002). No longer was it necessary for software to be free to be considered good.
"Open source" was proposed as an alternative to "free software." The purpose of launching the term was an attempt to promote open source as a software development model acceptable to corporate developers, those who had been reluctant to adopt a methodology connected to the moniker "free software" . The definitions of open source were taken from the Debian Free Software Guidelines  and adapted during June 1997 in relation to suggestions made during an email conference. After revisions the definition was adopted by the Open Source Initiative (OSI) in February 1998.
Despite the differences between the free software and open source movements, free software and open source software are most clearly defined by the licences that are approved by the respective organisation (either FSF or OSI). While the purpose of this paper is to look at the freedom debate, it is important to remain clear that both FSF and OSI refer to the same types of software products and licenses.
The freedom debate
The formalisation of the FSF’s philosophy is most clearly stated in the GPL in which the preamble states: "The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software — to make sure the software is free for all its users." More specifically the freedom envisioned by FSF and formalised in the GPL concerns the socalled four freedoms, which are the freedom to:
- run the program, for any purpose (freedom 0).
- study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this.
- redistribute copies so you can help your neighbor (freedom 2).
- improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.
Free as in beer and gift culture
The Free Software Definition establishes criteria for a program to be considered "free." There is an interesting clarification about the concept of freedom so that the reader will not be confused. Readers are asked to think of "free" in terms of free speech rather than "free beer" . Aside from being a rather unique metaphor in the debate on freedom, the free speech/free beer dichotomy adequately captures the conflicts involved in the term "free" in relation to computer software.
Aside from being a rather unique metaphor in the debate on freedom, the free speech/free beer dichotomy adequately captures the conflicts involved in the term "free" in relation to computer software.
The problem with freedom
The critics of the term "free software" argue that the term has many weaknesses  and that these weaknesses prevent the movement from gaining the widespread acceptance it both needs and deserves. Their primary concern is over the misleading meanings in the word "free." The word, according to them, in relation to software means "at no cost." Despite the free speech/free beer clarification, the term "free software" equally applies to all software available at no cost, such as Microsoft Explorer. However both the Free Software Foundation and the Open Source Initiative agree that the Explorer browser is not free in that its code is not widely available.
The problem therefore arises when one attempts to define what free software is to the world at large. In many cases computer users have not reflected upon the ownership of software. In relation to software such as Web browsers most computer users tend to consider such software as being free since it is freely available at no cost. In some cases there is no cost but the use of the software is either limited or connected with nonmonetary payment (see, for example, Eudora Mail  or Opera browser  sponsored mode). The many different financing models of computer software lead to a confusing diversity of software business models all which have the effect of obfuscating the concept of monetary cost for software users.
Ambiguity on both sides
The accusations of ambiguity have led the FSF to publicise additional material both defending their view and terminology as well as critiquing the OSI for there lack of precision and for confusing the users (Stallman, 2002). The choice of certain users within the free software community to start using the term open source was seen as a serious threat to the philosophical basis of free software. In 1998 Stallman (2002) wrote: "The Free Software movement and the Open Source movement are today separate movements with different views and goals, although we can and do work together on some practical projects."
The rift between the movements was therefore not so great that they could not cooperate on certain projects but it was serious enough that they no longer could identify ideologically with each other. Both movements are however in agreement upon their common enemy which they see as proprietary software. Therefore they share a common enemy but a fundamental difference in how they define themselves and both groups believe it to be important to protect their identity despite the fact that they share a common background. Stallman (2002) continues: "We are not against the Open Source movement, but we don’t want to be lumped in with them. We acknowledge that they have contributed to our community, but we created this community, and we want people to know this. We want people to associate our achievements with our values and our philosophy, not with theirs. We want to be heard, not obscured behind a group with different views."
The OSI organisation and terminology was created to meet the needs both of those developers who were disenchanted with the view that software needed to be ideologically pure as opposed to functional and of those developers who were attempting to entice more traditional software manufacturers to join the free software/open source movement. However, Stallman understood the OSI to be a weakening of a strong moral position in the debate; he appealed to developers not to accept this easy compromise (Williams, 2002). Despite Stallman’s warnings, the growth and development — both economic and political of open source has been massive. The creation of the OSI has entailed the creation of an umbrella organisation which has subsumed the FSF. Despite this, the FSF and the GPL still remain the more stringent and philosophically coherent organisation and license.
Licenses are a form of contract, often seen as standard form contracts not requiring parties to actively read and agree with each detail to be valid and enforceable . Licenses (such as a driving license) are commonly used to grant the licensee the freedom or permission to do something, which without the existence of the license would be wrongful or illegal. Licenses trace their origins in property where the license amounts to permission to enter the land owned by another; additionally they could also grant permission to hunt or remove items from the property. Bare or gratuitous licenses are revocable at the pleasure of the licensor (i.e., the owner of the property who grants the permission). Contractual licenses may be coupled with an interest and may through this interest grant the licensee the ability to enforce the license should the licensor attempt to revoke it. This ability depends upon the terms of the license.
When looking at software licenses it may be of interest to notice the licenses for software often fall into different types: proprietary, academic, reciprocal, standards, and content licenses (Rosen, 2004).
Proprietary licenses are possibly the most restrictive of all licenses and are commonly used in most commercial software when the source code is not made available. No distribution is permitted for original or derivative works, no license is granted for the user to view, attempt to view, or recreate the code. The term proprietary license is however not exact and variations on what is permitted regularly occur. Despite this, the term has come to reflect the antithesis of software freedom.
Academic licenses recognize that many free software/open source projects were developed within academia where the main drive was to spread their use. Therefore the users were granted full freedom, provided that they attributed the original to a given academic organisation. The reciprocal license allows the users to use and modify the software provided that all derivatives grant the same freedom to its future users . Standards licenses attempt to develop and maintain industry standards and require that deviations from industry standards be made public. Content licenses are concerned with ensuring that copyrightable subject matter be made freely available.
The concept of free software as envisioned by the Free Software Foundation was not created in a vacuum. The General Public License (GPL) was based upon the concept of reciprocity. The goal of forcing developers to maintain the same amount of freedom has had the effect of creating "open" or "free" software which enables future users to continue to develop and expand the amount of software available.
Section 2b of the GPL reads "You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License." This means that any software created from the original GPL must continue to be offered under the same terms. Moglen (1999) maintains that this clause ensures users always have the best available software. Critics claim that this means that widespread commercial development cannot take place, nor will commercial companies dare to use any part of GPL software in their products. The latter critique has led the GPL to be seen as largely anticommercial.
Rosen (2004) defines reciprocity as the " ...mutual interchange of favors or privileges. Something is reciprocal when it is performed, experienced, or felt on both sides." Both sides of the GPL (licensor and licensee) both use the GPL. However it is interesting to note that the GPL constricts the user since any derivative works must be licensed under the same terms. In a sense the developer is forced to contribute to the commons . The contributor does not contribute freely. If all developers wanted to contribute in this manner to the commons they would not be doing so freely.
The license therefore is a fundamental element of the creation of a commons where software is available. The goal, as stated by Stallman in his original email, is to create and expand a software commons. The expansion of the commons is, however, not compatible with the terminology of freedom used both in the name of the organisation and in the rhetoric it espouses. The freedom created by the GPL has limitations in relation to price (cf. §2b), patents (cf. §7) and authorship (cf. §10). While many of these limitations are not experienced as limitations since they are part of the free software developer’s ethos it is important to note that they are limitations. In discussing freedom, we must be careful about confusing freedom with happiness. An unfree person may be happy as easily as a free person is unhappy.
Raymond (1999) notes that "Freedom is not an abstract concept in business. The success of business is almost directly related to the degree of freedom the suppliers and the customers of that industry enjoy."
The importance of freedom, its attainment and preservation, has been the topic of discussion in every society. However the definitions and contents of freedom vary over time and place. The Stoics’ discussions on freedom, for example, are very reminiscent of present day discussion on determinism and free will (Bobzien, 2001).
Today an accepted systemisation of freedom into negative and positive freedoms, with its roots in Kantian (2003) thought, is a popular theoretical construct. The concepts of negative and positive freedom were developed by Berlin (2002). Negative freedom is commonly seen as the absence of barriers or constraints which prevent actors from carrying out their wishes or desires. Positive freedom deals with the existence of enabling factors which create the ability for the actor to carry our desires. An alternative approach is to look at negative freedom as external forces on the actor while positive freedom concerns the internal forces affecting the actor.
In terms of state actions the liberal view is one of negative freedom and minimal state interference while those who argue for positive freedom understand that the removal of barriers is not enough to create freedom. Active positive freedom in social terms can be seen when individual freedom is achieved by actively participating in the decisionmaking processes of society. In its best form, the rules of society are then a reflection of the general will based upon selfdetermination. Members of such a society are free only to the extent that they participate in the creation of society (Rousseau, 1998).
Those who argue for positive freedom point to the fact that the removal of barriers is too simplistic to create freedom. For example anyone born in the United States can become president. Those who subscribe to negative freedom will point to the fact that there are few or no barriers, while those who argue for positive freedom would point out that despite this lack of barriers no president has been female, openly gay, or from a nonwhite minority. In other words, the removal of formal barriers is a necessary precondition but does not de facto create a larger freedom of action for the individual.
Positive freedom, on the other hand, is criticised for its authoritarian tendencies since it requires the paternalism of other actors to provide for the encouragement of the concept of freedom in others. Additionally, positive freedom carries with it a paradox when dealing with an oppressed minority. No matter how much the minority participates in the decisionmaking process it will remain oppressed and cannot be seen as free.
An issue which we have not yet dealt with here is the role of the actor’s desire. In other words, is it the actor or the surroundings which decides whether the situation is free or unfree? Prison is the symbol of lack of freedom. Are perfectly content inmates unfree if all their desires can be fulfilled? The prisoners are, relatively speaking, content and therefore do not suffer from their lack of freedom. Those who espouse positive freedom would therefore conclude that these prisoners are free. Some argue that freedom cannot be limited to what one wants to do but must also include what one might want to do.
In attempting to understand this form of free will, which includes what one might want to do in the future, it is important therefore to understand the actors’ motives. Christman (1991) uses the example of women raised in cultures where women are subservient to men. A woman’s desire to conform in such a society may be her own desire or it may be a role from which she cannot rebel. Positive freedom theorists would argue that the woman is unfree since her views were formed in an oppressive environment. Most theorists would consider that if the desire to conform is her own, then forcing an alternative view of freedom upon her would not increase her individual sense of freedom.
There is an alternative approach to this binary definition. We have noted the "freedom to" (positive) and "freedom from" (negative) approach to understanding notions of freedom. Another way of looking at freedom is the socalled triadic model (MacCullum, 1967) which states "A (Agent) is (or is not) free from B (Obstacle) to achieve, be, or become C (Goal)." The triadic model was important in showing the error in attempting to distinguish between freedom as the absence of constraint and freedom as the possibility of choice.
In recent years some have argued that freedom is a social relation (Kristjánsson, 1996; Kramer, 2003) by which they argue that there is a difference in being unable to do certain things and being unfree. Being unable to do things due to natural causes (men cannot give birth, blind cannot see) is not being unfree. However this view of looking at freedom or lack of freedom as dependent upon human acts is troublesome in relation to computer software. The underlying assumption is that nonsocial causes of a lack of freedom fall outside the scope of interest of philosophers, becoming merely an engineering or medical problem.
However if we ignore discussing notions of freedom in relation to software, we seriously create risks for the future by creating an unfree infrastructure that potentially could be a major hindrance. Future users hence run the risk of being unable to contemplate a scenario where this lost freedom is even an option. This is much the same problem that Orwell (1990) presented where the only meaning of free is to be free from something. Therefore a dog could be free of fleas but the concept of human freedom is incomprehensible.
Freedom should not be limited to the possibility of doing things but it should guarantee the possibility of providing the possibility of carrying out acts once a rational wellinformed decision has been reached.
Negotiating freedom & property
Within the human rights tradition, it is almost taken for granted that the concept of property is a fundamental part of human freedom . However the concept of property does not always easily coexist with freedom. Anarchists, such as Proudhon (1840), claim that all property is theft, meaning both that property is a prerequisite for theft and the accumulation of property amounts to theft since it deprives others.
In law, the concept of property refers to the legal relationships between persons in relation to things. These things may be tangible such as real estate or pencils or they may be intangible such as stocks, patents, or software. As in many other areas, the protection offered by the law and the way in which it is offered varies greatly. The law in relation to property exists in every legal system but the scope and manner in which protection is created and enforced depends very much on the culture, both where and when, in which the legal system was created.
Common amongst the concept of property law is that it deals with the accumulation, protection, use, and limitation of wealth and therefore has serious repercussions on many other aspects of society. A characteristic of the core European legal systems is the predominance of private ownership. Western legal systems regard individual ownership as the norm, derogations from which must be explained. The legal concept of property in the West is characterized by a tendency to agglomerate in a single legal person, preferably the one who is currently in possession of the thing in question, the exclusive right to possess, privilege to use, and power to convey the thing.
Property is not often seen as a static condition but rather is viewed as a relationship between a person (or persons) who owns, the things which are owned, and actions affected by ownership. The word ownership is not especially clear since it seems to denote a single relationship to that which is owned. In reality ownership is a collection, or bundle, of rights which complement each other and grant to the owner the authority to legitimately enforce conditions. Stated more simply, ownership allows the owner to enjoy that which is owned and prevent others from similarly enjoying that which is owned.
In addition to this, the owner may grant others the right to enjoy that which is owned. This permission may be connected to conditions and fees. Under the law today most tangible things may be owned, but there are exceptions (cf. hazardous goods, narcotics, wild animals, important waterways) which limit full property rights through specific rules. Intangibles are more complicated under the law. This is not due to any lack of historical or traditional intangible ownership (Sherman and Bently, 1999) but is due to the focus on the concept of possession.
Today the concepts of property have been extended to cover many forms of intangibles. These intangible include software, even though this extension is not without its critics. Moglen (1999) noted that treating software as property has the effect of creating bad software.
Property theory is deceptively easy. Property today implies exclusive privilege of the thing in question. Despite the difficulties in attributing property rights to intangible objects, the legal institutes of copyright and patents have been created to create exclusive propertylike relationships and grant property rights on certain symbols, images, and intangible matter. This has led to the expansion of property to encompass a larger sphere. That which is owned is no longer simply the item itself but the privileges which it provides to the owner (Harris, 1996).
Copyright prevents the use of a copyrightable object without permission. That which is copyrighted cannot be reproduced in any form. Copyright does not only ensure the owner has exclusive rights to enjoy a property but also ensures that the property cannot be recreated by anyone else — even if this recreation does not diminish the copyright holder’s enjoyment. This sentiment was criticised by Thomas Jefferson (1903) when he wrote:"If nature has made any one thing less susceptible than all others of exclusive property, it is the action of the thinking power called an idea, which an individual may exclusively possess as long as he keeps it to himself; but the moment it is divulged, it forces itself into the possession of every one, and the receiver cannot dispossess himself of it. Its peculiar character, too, is that no one possesses the less, because every other possesses the whole of it. He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. That ideas should freely spread from one to another over the globe, for the moral and mutual instruction of man, and improvement of his condition, seems to have been peculiarly and benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density in any point, and like the air in which we breathe, move, and have our physical being, incapable of confinement or exclusive appropriation. Inventions then cannot, in nature, be a subject of property."
Intellectual property moves beyond control of the physical object which is in itself only the manifestation of that which is protected. Intellectual property controls the way in which property may be used insomuch as it controls all forms of use, even those which do not enrich or harm the original owner. In relation to software this problem becomes more acute since it does not take into consideration the needs of stakeholders such as users and other developers.
The western view of property has led to an increase in the privatisation of commodities which traditionally were held in a commons. Natural resources necessary for the survival of all within a society have become privatised. An example of this can be seen in the most basic of commodities: water. Traditional and older legal sources hold access to water to be a common property; with the development of more efficient technology , water has become a commodity (Shiva, 2002).
The quest of the Free Software Foundation is to create a software commons. This is not about the recreation of something which was free but is now lost but instead the realisation that software is becoming an essential element of the modern world. To lose control of software and to become dependent on the private property of others is tantamount to the loss of water rights, becoming dependent upon the goodwill of others.
The disappearance of the European commons occurred during the 17th century with the enclosure movements. These movements were legitimised by philosophers such as Locke (1998), whose view that idle nature was wasteful and the adding of labour to land was enough to create property. Property occurred since " ...every man has a Property in his own Person. This no Body has any Right to but himself. The Labour of his Body, and the Work of his Hands, we may say, are properly his."
With this the stage was set for the commoditisation of nature. "Whatsoever then he removes out of the State of Nature hath provided, and left it in, he has mixed his Labour with, and joined to it something that is his own, and thereby makes it his Property." Locke has since then been used to legitimise the creation of new property rights in tangibles and intangibles.
Today the concept of commons is associated with inefficient and wasteful usage of property — Hardin (1968) goes so far as to ask us to view the commons as a tragic waste of resources. The commons, from Hardin’s perspective, are pastures, free for all to use, where cattle graze freely. Under economic theory, individual cattle owners will all strive to maximise their own stock and this will lead to the destruction of the pastures. Hardin sees the commons as a place without rules (legal or social) where all actors strive to maximise their own economic wealth. However, for Hardin’s tragedy to occur several assumptions about the commons must be made (Shiva, 2002).
Hardin assumes that all human interaction is based upon competition and not cooperation and that property held in commons is unregulated. Communities dependent upon the commons do not have social regulations and that group ownership is an inferior solution.
Stallman’s position in the freedom debate arises from a realisation about the necessity of a software commons. However Stallman shares Hardin’s flawed views of the commons. The position that freedom is good may be acceptable but freedom cannot be enforced and limited in the way in which the FSF attempts to do so. Since users are controlled by the GPL and they are reliant on licenses any freedom which they may have or experience is on the whole illusory. True freedom would allow all to do as they pleased. However, Stallman shares Hardin’s view that uncontrolled freedom inevitably leads to ruin. Therefore the commons he creates is not a free one. It offers only limited freedom maintained and controlled by an elite .
In his attempts to establish a commons Stallman pushed for the creation of a freedom with severe limitations. While these limitations may be necessary for the creation of the commons they are most definitely limitations. This establishes the paradox at the heart of the free software debate which is then confused with notions of free. The use of the word free however is important to those within the FSF since it provides positive reinforcement for the ultimate goal of a commons.
However the OSI have not necessarily chosen a better approach. By abandoning the established path laid out by Stallman, OSI may have appeased commercial interests but they have muddied the philosophical waters of the free/open software movement. Both groups (FSF and OSI) have suffered. Any gain which may have been achieved by enticing economic cooperation has occurred at the expense of the original notion of software freedom. While there may now be an increase in open source software, there are fewer debates over some basic philosophical issues. In translating this debate into terms which are easily comprehensible to commercial actors we have lost the most important element of the debate — who should own the most fundamental elements of our infrastructure?
About the author
Mathias Klang is based at the University of Göteborg where he lectures regularly on the relationship between rights and technology. Mathias is the Project Lead for Creative Commons Sweden (www.creativecommons.se). He recently edited, with Andrew Murray, the book Human rights in the digital age (London: GlassHouse, 2005; and at (www.digital-rights.net).
Email: klang [at] ituniv [dot] se
I owe very much to discussions with Lennart Petersson, Jonas Öberg and Karl Jonsson; they have also commented on early drafts of this paper. Despite their best efforts to correct me, errors remain my own. In addition I would also like to thank the students of the free software/open source theory and philosophy course.
8. I would like to thank Professor Christina Ramberg for our discussions on contracts and licenses.
9. This is often known as the viral effect by those who dislike the practice and the vaccination by those who support it.
10. Alternatively not spreading it at all.
11. Universal Declaration of Human Rights, articles 2 and 17.
12. The GPL is controlled by an elite since only a very limited number have the power to affect changes to the GPL.
J.M. Balkin, 1998. Cultural software: A theory of ideology. New Haven, Conn.: Yale University Press.
Isaiah Berlin, 2002. Liberty. Oxford: Oxford University Press.
Susanne Bobzien, 2001. Determinism and freedom in stoic philosophy. Oxford: Oxford University Press.
Manuel Castells, 1996. The information age: Economy, society, and culture. Oxford: Blackwell.
John Christman, 1991. "Liberalism and individual positive freedom," Ethics, volume 101 (January): pp. 343359. http://dx.doi.org/10.1086/293292
Garrett Hardin, 1968. "Tragedy of the commons," Science, volume 162, pp. 12431248. http://dx.doi.org/10.1126/science.162.3859.1243
J.W. Harris, 1996. Property and justice. Oxford: Oxford University Press.
Thomas Jefferson, 1903. "Letter from Thomas Jefferson to Isaac McPherson" (13 August 1813), In: Andrew A. Lipscomb and Albert E. Bergh (editors). Writings of Thomas Jefferson. Washington, D.C.: Thomas Jefferson Memorial Association of the United States, volume 6, pp. 330, 333334; and also at http://press-pubs.uchicago.edu/founders/documents/a1_8_8s12.html, accessed 5 March 2005.
Immanuel Kant, 2003. Critique of pure reason. Hampshire: Palgrave Macmillan.
Matthew H. Kramer, 2003. The quality of freedom. Oxford: Oxford University Press.
Kristján Kristjánsson, 1996. Social freedom: The responsibility view. Cambridge: Cambridge University Press.
John Locke, 1998. Two treatises of government. Cambridge Texts in the History of Political Thought. Cambridge: Cambridge University Press.
G.C. MacCallum Jr, 1967. "Negative and positive freedom," Philosophical Review, volume 76, pp. 312334. http://dx.doi.org/10.2307/2183622
William J. Mitchell, 1996. City of bits: Space, place, and the infobahn. Cambridge, Mass.: MIT Press.
Eben Moglen, 1999. "Anarchism triumphant: Free software and the death of copyright," First Monday, volume 4, number 8 (August), at http://www.firstmonday.org/issues/issue4_8/moglen/, accessed 5 June 2005.
Nicholas Negroponte, 1996. Being digital. New York: Vintage Books.
PierreJoseph Proudhon, 1994. What is property? Cambridge: Cambridge University Press.
Eric S. Raymond, 1999. The cathedral and the bazaar: Musings on Linux and open source by an accidental revolutionary. Sebastopol, Calif.: O’Reilly & Associates.
Lawrence Rosen, 2004. Open source licensing: Software freedom and intellectual property law. Upper Saddle River, N.J.: Prentice Hall.
JeanJacques Rousseau, 1998. The social contract. Translated by H.J. Tozer. Ware, U.K.: Wordsworth Editions.
Brad Sherman and Lionel Bently, 1999. The Making of Modern Intellectual Property Law. Cambridge: Cambridge University Press.
Vandana Shiva, 2002. Water wars: Privatization, pollution and profit. Cambridge Mass.: South End Press.
Richard Stallman, 2002. Free software, free society: Selected essays of Richard M. Stallman. Boston: Free Software Foundation.
George Orwell, 1990. 1984. London: Penguin.
Sam Williams, 2002. Free as in freedom: Richard Stallman’s crusade for free software. Sebastopol, Calif.: O’Reilly & Associates.
Paper received 19 January 2005; revised 9 February 2005; accepted 28 February 2005.
Copyright ©2005, Mathias Klang.
Free software and open source: The freedom debate and its consequences by Mathias Klang
First Monday, volume 10, number 3 (March 2005),