Κυριακή, 24 Φεβρουαρίου 2008

Open source software


Open source software is defined as computer software which source code is available under a license that meets the open source definition. This permits users to use, change, and improve the software, and to redistribute it in modified or unmodified form. Those rights granted to users by the licenses of open source software would otherwise be prohibited by copyright. Therefore, it becomes apparent that open source software constitutes a challenge for copyright law, which is based on the assumption that intellectual creations are to be protected with absolute rights.

The idea of free software developed out of the need expressed by programmers to be able to adapt existing software to their specific requests. That was not possible, since proprietary software was not supplied with the source code and, so, changes could not be performed. In addition, legal holders did not provide any permission to adaptation of software and so, changes in the source code would infringe author’s rights.

In order to overcome such problems, the Free Software Foundation was founded by Richard Stallman in 1983 in the USA, with the objective of developing free software, i.e. software available with source code to everyone and free of charge. The idea was to allow users of software to profit from the further development made by others, since the modifications are in turn made available free of charge.

The aim of this FSF was to promote free dissemination of software and secure this freedom in legal terms. In this context, free does not mean free of charge. According to Stallman, free software refers to freedom, not to price. And more particularly, free software is a matter of the users' freedom to run, copy, distribute, study, change and improve the software.

More precisely, four kinds of freedom for the users of the software are included in the definition of free software:

  • The freedom to run the program, for any purpose.
  • The freedom to study how the program works, and adapt it to your needs. Access to the source code is a precondition for this.
  • The freedom to redistribute copies so you can help your neighbour.
  • The freedom to improve the program, and release your improvements to the public, so that the whole community benefits. Access to the source code is, again, a precondition for this.

To safeguard the open character of free software, a new concept was evolved, the concept of ‘copyleft’. More precisely, putting a computer program in the public domain would mean that anyone could include it in its derivative software, which could have a proprietary and not an open character, and this would contravene with the objective of free software development. Therefore, a new concept had to be invented, one that would use copyright law to protect the free character of the software. In the words of Stalmann:

To copyleft a program, we first state that it is copyrighted; then we add distribution terms, which are a legal instrument that gives everyone the rights to use, modify, and redistribute the program’s code or any program derived from it but only if the distribution terms are unchanged.

The concept of free software was further developed in 1997, with the formation of the open source concept, which is more liberal than free software and allows software to be included more appropriately in proprietary programs. This would allow the recognition of open source software by commercial software developers and as a result, lead to its wider acceptance.

In order for any computer program to fall within the qualification of open source, it should comply with the definition of open source software. In more particular, the OSD contains the following provisions:

1. Free Redistribution

The license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.

An OSD license may not restrict any third party from including the software as a part of their product.

2. Source Code

The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of obtaining the source code for no more than a reasonable reproduction cost preferably, downloading via the Internet without charge. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed.

3. Derived Works

The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.

4. Integrity of The Author's Source Code

The license may restrict source-code from being distributed in modified form only if the license allows the distribution of "patch files" with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software.

5. No Discrimination Against Persons or Groups

The license must not discriminate against any person or group of persons.

6. No Discrimination Against Fields of Endeavor

The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.

7. Distribution of License

The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties.

8. License Must Not Be Specific to a Product

The rights attached to the program must not depend on the program's being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program's license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution.

9. License Must Not Restrict Other Software

The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.

10. License Must Be Technology-Neutral

No provision of the license may be predicated on any individual technology or style of interface.

Licences

Furthermore, open source software is made available under a particular license. Currently, the OSI website lists 65 types of licenses, which are more or less restrictive, in the sense that they allow the creation of proprietary programs from the original code or keep the derivative code in control.

The most important and highly restrictive license is the General Public License. The main features of the GPL is that it is persistent, for all the derivative works must be licensed under the same GPL and has viral effect, which means that if a piece of GPL code is included in a new program incorporating both open and closed source code, then the resulting program must become open under the GPL.

The terms and conditions of the GPL

Any licensee who adheres to the terms and conditions is given permission to modify the work, as well as to copy and redistribute the work or any derivative version. The licensee is allowed to charge a fee for this service, or do this free of charge. This latter point distinguishes the GPL from software licenses that prohibit commercial redistribution. The FSF argues that free software should not place restrictions on commercial use, and the GPL explicitly states that GPL works may be sold at any price.

The GPL additionally states that a distributor may not impose "further restrictions on the rights granted by the GPL". This forbids activities such as distributing of the software under a non-disclosure agreement or contract. Distributors under the GPL also grant a license for any of their patents practiced by the software, to practice those patents in GPL software.

Section three of the license requires that programs distributed as pre-compiled binaries are accompanied by a copy of the source code, a written offer to distribute the source code via the same mechanism as the pre-compiled binary or the written offer to obtain the source code that you got when you received the pre-compiled binary under the GPL.

The right to redistribute is granted only if the distribution is licensed under the terms of the GPL and includes, or unconditionally offers to include at the moment of distribution, the source code.

Advantages of OS

It is argued that open source brings about significant advantages compared with proprietary developing projects. These refer to economic and technical rationales. Collaborative work and peer-to-peer review of open source means that research and development costs are reduced. Furthermore, the result is better quality of code and thus, open source software offers more reliability to users and software developers.

Regarding the question what motivates people to write free software it could be said that while traditional closed source programming offers immediate payoff, the open source model has some other strengths, such as customisation and bug-fixing. In more particular, the participation in an open source project is more meaningful to a programmer if it brings a personal benefit, i.e. to tailor a piece of code to suit his own project.

Of course, the motivation to write free software could not be an expression of “neighbourly love” or the necessity to treat software as public property, as the activists of the Free Software Foundation claim. Actually, the aim is to break the privileges of intellectual property and thus to ensure free exchange of information. This in turn, would weaken the position of companies like Microsoft, which act like monopolies in the software marketplace. It is a logical consequence, therefore, for such companies to feel threatened by open source initiatives.

The Legal validity of open source licenses

As the open source initiative depends on copyright, it has been long disputed whether non-proprietary licenses used to control open source works are legally valid and whether this initiative would withstand legal attacks. It is encouraging that there is a increasing number of software projects using free and opens source software licenses; sourceforge which functions as a repository for open source software lists more than 160,000 projects and 1,700,000 users.

Legal analysis of such licenses both in the States and in Europe carried out in the literature indicated their validity. The most important development is, however, that their validity has been tested before the courts and was thereby recognized.

The first case was in 2002, when a developer of non-proprietary database software named MySQL sued NuSpehre, a software company that was believed was using its source code to produce proprietary software, for copyright and trademark infringement in US district court. The case was settled out of court, and so, the GPL did not receive a judicial review, however, at the hearing Judge "saw no reason" that the GPL would not be enforceable.

The next case was the lawsuit of SCO against IBM, in which the claimant alleged that IBM was infringing its intellectual property over the UNIX kernel by including it in Linux. SCO also sent a letter to 1350 corporations using Linux warning that this was un unauthorised derivate if Unix. However, on August 10, 2007, it has been ruled out that Novell, not the SCO Group, was the rightful owner of the copyrights covering the Unix operating system. Consequently, Novell announced they have no interest in suing people over Unix, and so the legal uncertainty over Linux ended.

In another occasion, the FSF was suited in an US district court in Indiana, by a US citizen who claimed that the GPL is an illegal attempt to fix prices at zero. This case was dismissed for it did not constituted a valid anti-trust claim. Notably, the court noted that "the GPL encourages, rather than discourages, free competition and the distribution of computer operating systems, the benefits of which directly pass to consumers.

In Europe, the validity of the GPL was put to test in the courts of Germany. In 2004 the Munich District Court held that the license conditions of the GNU General Public License were standard terms of business and could be included in a contract with a commercial software company, and so it granted the claimant, netfilter/iptabels, an injunction against Sitecom, a company which distributed netfilter’s software in violation of the terms of the GPL. In another case, the gpl-violations.org project prevailed in court litigation against D-Link Germany GmbH regarding D-Link's alleged inappropriate and copyright infringing use of parts of the Linux Kernel. The court provided legal precedent, according to which the GPL is valid and will stand up in court.

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