The term “open source” describes the practice of producing or developing certain finished products, allowing users to access the production or development process freely. Some specialists define the “open source” as a philosophical concept; others think it is a pragmatic methodology.
Being very often used in software development, many programming specialists have the impression that “open source” is a specific notion of this activity. In fact, “open source” can be applied in any domain where a product is produced or developed. There are examples of such applications in technology, medicine, education, culture and more.
Open source software is software developed by a community, by a company or by a person, and offered for use under a free license that guarantees the access of all users to the source code.
Examples of open source programs: qBittorrent, Blender (3D graphics), Pidgin (client for instant messaging), lots of GNU / Linux distributions, Mozilla Firefox (browser), OpenOffice.org.
The GNU/Linux operating system is comprised entirely of open source software, some GNU/Linux distributions being free, others at a commercial cost.
Free software is characterized by the freedom of its users to use, copy, redistribute, study, modify, and enhance it. Specifically, it is about the following four forms of freedom for its users:
1. Freedom to use the program for any purpose (also called “freedom 0”).
2. Lobbying to study the way the program works, and to adapt it to your own needs (“freedom 1”). “Open source” provides access to all source code.
3. The freedom to redistribute children to help your neighbor (“Freedom 2”).
4. Lobbying to improve the program, and make improvements available to the public for the benefit of the whole society (“Freedom 3”), thus requiring access to the source code.
A program (an application) is Free Software if it meets all these freedoms. Thus, anyone who should be free to redistribute copies, whether modified or not, free of charge or for a fee for the cost of selling. These freedoms mean (among others) that it is not necessary to ask or pay for permission to do so. There must also be the freedom to make changes and use them both for personal and professional or recreational purposes, without being obliged to mention to someone that these changes exist, a situation that also applies when changes are made public.
The idea behind Open-source is one pretty simple: when programmers can read, distribute and change the code, the code will mature.
People can adapt, repair, explore defects, and can do this at a speed that blurs the performance of program developers in well-known companies.
These programs will be more flexible and better quality than programs that have been developed on conventional channels because they have tested more people under conditions different from those in which proprietary software developers can do so. The Open Source initiative has begun to emerge in the commercial world and, very slowly, distributors understand its point of view.
While many people in the academic and engineering world have already been convicted for nearly 20 years now that this is the way to go, distributors in the world of commerce needed applications like the Internet to realize that they can also take advantage of Open Source. Now Linux has passed the stage where it was almost exclusively an academic system, useful only for a handful of technically skilled people.
Linux provides more than just an operating system: there is an entire infrastructure that supports the effort required to build an operating system, write and test programs to bring the fruits of the effort to users, maintain maintenance, support, updates, and customizations.
In practice, the term “free software” designates software whose source is accessible and can be studied, modified, improved and distributed (the four freedoms of free software). The term “open source software” designates software with the accessible source where the copyright holder offers the above-mentioned rights, but can limit them, for example, does not allow the distribution of modified versions of the source code.