Open Source Software

Open source software is software where the source code is freely available. Users are free to make improvements and redistribute as long as they abide by certain conditions (see How does an open source licence work?). The most famous OSS is the operating system, Linux.

Conversely, the source code for proprietary software is generally kept secret. A user purchases only the compiled version of proprietary software and has no choice but to use the software 'as is'.

Source code is the high-level programming language that human programmers use to build computer programs. Anyone educated in a particular programming language (e.g. C++, java) can understand and edit source code in that language.

Compiled code is source code translated or compiled into a language that computers can understand (compiled code is also called binary code). Humans can not understand or edit compiled code. Even specialized programs, designed to reverse-compile, cannot reproduce perfect source code from compiled code.

Sir Isaac Newton is famously quoted as saying: If I have seen further it is only by standing on the shoulders of giants. Open source software development embraces this principle. Open source is a community-centric development model, which encourages the free flow of knowledge and insight between all members. The open source model does away with organizations and central control, replacing them with open networks of individuals. Every individual can build on the work that has been done by others in the network; no time is spent reinventing the wheel.

Figure 1: The Open Source Model: Source code is available to public. The public is free to make improvements.

Figure 2: The Closed Model: The Microsoft source code is closely guarded. The User only receives a compiled version of the software. Modification is impossible.

In recent years, the linking of individuals has been enhanced by the Internet's high-speed data capacity and omnipresence. With efficient networking infrastructure in place, the collaborative open source model has limitless potential. In fact, over the last decade open source software licences have been embraced internationally and are already in force for thousands of computer programs.

In 1984, Richard Stallman started the GNU project. The GNU project's goal was, simply put, to make it so that no one would ever have to pay for software. The first step was to develop a complete UNIX style operating system, the GNU system. The GNU system would become the first 'free' software.

In Copyleft: Pragmatic Idealism, Stallman describes the motivation behind free software:

My work on free software is motivated by an idealistic goal: spreading freedom and cooperation. I want to encourage free software to spread, replacing proprietary software that forbids cooperation, and thus make our society better.

Stallman expands on why free software makes society better:

What does society need? It needs information that is truly available to its citizens---for example, programs that people can read, fix, adapt, and improve, not just operate. But what software owners typically deliver is a black box that we can't study or change. Society also needs freedom. When a program has an owner, the users lose freedom to control part of their own lives. And above all society needs to encourage the spirit of voluntary cooperation in its citizens. When software owners tell us that helping our neighbours in a natural way is "piracy", they pollute our society's civic spirit.

The difference between the movements is not concrete. The 'open' collaboration model used for software development is the same for both free software and open source. The only pronounced distinction is ideological. 'Free software' software development is motivated by an altruistic desire to improve society at large; society comes first and individual commercial gain is a distant second (to put it mildly). 'Open source' development is motivated by a belief that the development model is superior to proprietary models. The open source movement is an offshoot of the free software movement. It puts a more pragmatic, less dogmatic face on the development model, making it more palatable to mainstream developers. Nevertheless, much of the present success of the 'open source' movement is due to the Free Software Foundation doggedly championing the framework.

Open-source developers have the opportunity to build on each other's ideas. The availability of OSS source code allows a worldwide community of open-source developers to participate in peer-distribution, peer-review, and peer-production. A program can be improved and redistributed ad infinitum, benefiting the entire community. As the open source model of openness and collaboration expands, the quality of OSS products also improves.

The issue of overall quality aside, OSS has four inherent advantages over proprietary software. First, open-source software is considerably less expensive than proprietary alternatives. For example, Linux can be installed for free while Microsoft's Windows operating system can cost thousands of dollars a month to license. Second, access to underlying source code means users can detect and fix programming bugs; also, OSS can be tailored to a user's specific needs, and upgrades happen at a pace chosen by the user, not the vendor. Third, the transparency of OSS improves security because security flaws can be detected and corrected. Fourth, open source allows users to be flexible in their choice of vendors. If users are not happy with the service they receive from Red Hat, they can choose another Linux vendor. This prevents users from becoming overly dependent on their technology or support contracts.

Liability for intellectual property infringement

The typical open source project contains contributions from many people. It is almost impossible to audit the entire code base for violations of previous licence conditions. This creates many opportunities for contributors to introduce infringing code. Thus this risk in the development process is largely borne by licencees. Contributors do not vouch for the integrity of the code they contribute to the project; in fact, the opposite is true -- the standard open-source licence is designed to be very protective of the contributor. The typical licence agreement does not include any intellectual property representations, warranties or indemnities in favour of the licencee; instead, it contains a broad disclaimer of all warranties that benefits the licensor/contributors.

Recent litigation in the U.S. highlights this risk. There has been a flurry of lawsuits surrounding the SCO Group's (SCO) claim that its proprietary code was incorporated into the open-source Linux operating system. SCO has also claimed general invalidity of the GPL, although it is not clear that SCO will persist with this assertion.

  No guarantee of quality or fitness

Some open source software projects, such as the Linux initiative, have one or more stewards who monitor code quality and track bugs. Other initiatives, however, are the product of hobbyists and do not enjoy the same code quality and rigorous testing protocol. Without contractual commitments of quality or fitness, the licencee must accept the risk that the software contains fatal errors, viruses or other problems that may have downstream financial consequences.

  Copyleft Licensing

As mentioned above, some open-source licences, such as the GPL, require licencees to provide royalty-free copies of their derivative works in source code form for others to use, modify and redistribute in accordance with the terms of the parent licence agreement (see Figure 3). This licensing condition makes it very difficult for companies in the commercial software business to use such open source software as a foundation for a business. As a result, companies may be concerned that the use of OSS within, or in connection to, their proprietary programs may convert their entire code base into a "derivative work" which would need to be made available royalty-free.