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Understanding the Open Source Philosophy
Open source is more than a way to publish code. It is a philosophy about how software should be created, shared, and improved. To understand Linux, you need at least a basic sense of this mindset, because Linux was born from it and still develops under its influence.
Source Code and the Idea of Openness
Every program is built from source code, which is written by humans in programming languages. When a program is distributed only in compiled form, users can run it but cannot easily see how it works or change it. Such software is often called closed source or proprietary.
Open source software makes the source code available to everyone. Anyone can read it, learn from it, study how things are done, and suggest or apply changes. This openness is the foundation of the open source philosophy.
An important statement: Open source is defined by access to source code and by legal permission to use, modify, and share that code.
The licenses that accompany open source software turn these ideas into clear rules and rights, so that developers and users know what they are allowed to do.
Open Source vs Free Software
There are two related but distinct movements behind Linux: free software and open source. They overlap in what they allow you to do with software, but they emphasize different values.
The free software movement focuses on user freedoms. Its central idea is that users should control the software they run, not the other way around. The word "free" in this context refers to freedom, not to price. You can have free software that costs money to obtain, but it must protect certain freedoms.
The open source movement focuses more on practical benefits and development models. It highlights how open development can produce better, more secure, and more flexible software through collaboration.
In practice, much of the software in the Linux world is both free software and open source software. The difference is mainly the philosophical framing and the language used to explain it.
The Core Freedoms
The free software tradition describes four basic freedoms that software should grant its users. They are usually expressed as freedoms labeled 0, 1, 2, and 3. Using a simple model, you can think of them as basic conditions:
Let $U$ represent "you as a user" and $S$ represent a software program. Then the freedoms can be summarized as conditions on your relationship with $S$.
- Freedom 0: The freedom to run the program as you wish, for any purpose.
Formally, for all uses $p$, $U$ may run $S$ for purpose $p$. - Freedom 1: The freedom to study how the program works and change it so it does what you wish. This requires access to the source code.
- Freedom 2: The freedom to redistribute copies so you can help others.
- Freedom 3: The freedom to distribute copies of your modified versions to others so the community can benefit from your changes.
Key rule: A program is considered free software only if it grants all four freedoms to every user.
Open source definitions from organizations such as the Open Source Initiative list similar requirements, framed slightly differently, but the basic idea is the same: users must have broad rights to use, study, modify, and share the code.
Licenses as the Legal Foundation
The open source philosophy becomes real through licenses. A license is a legal text that states what you are allowed to do with software and under what conditions.
Open source licenses differ in style, but they all allow you to:
Use the software for any purpose.
Access or receive the source code.
Modify the source code.
Share original or modified versions under certain rules.
Broadly speaking, there are two main families of open licenses in the Linux ecosystem.
The first family is permissive licenses. These include examples such as the MIT license or the BSD licenses. They allow you to do almost anything with the code, including incorporating it into closed source products, as long as you follow simple conditions like keeping copyright notices. In a simplified form, a permissive license says:
If $U$ complies with condition set $C$ (for example attribution), then $U$ may use, modify, and redistribute $S$ in any form.
The second family is copyleft licenses. The most notable example here is the GNU General Public License, often abbreviated as GPL. Copyleft licenses allow use and modification, but they add a reciprocity rule. If you distribute a modified version, you must also share your modifications under the same license and provide source code to your recipients.
Copyleft principle: If you distribute a modified version of copyleft software, you must grant your recipients the same freedoms you received and provide the corresponding source code.
Linux itself, meaning the kernel, is licensed under the GPL. This choice has strongly shaped how Linux evolves and how it is used in both community and commercial settings.
Collaboration and the Development Model
The open source philosophy promotes a collaborative way of working. Instead of one company holding all control, many individuals and organizations can contribute. The typical pattern is:
Someone writes an initial version of a program and publishes its source code under an open license.
Others discover it, report bugs, and propose improvements.
Changes are discussed, reviewed, and merged, often in public.
Over time, the project grows beyond its original author.
This shared model brings two important practical effects.
First, there is a wider pool of people who can inspect the code. Bugs and security problems can be noticed and fixed by anyone who has the skills and interest.
Second, the software can adapt to many different needs. If a particular user or company needs a new feature, they can add it or support someone else to add it instead of waiting passively for a vendor.
Linux is a prime example of this approach. It has thousands of contributors from individuals, companies, and distributions. Contributions are coordinated through public version control systems and mailing lists, and decisions are made by maintainers who review and accept patches.
Transparency and Trust
Another essential part of the philosophy is transparency. Because the code is visible, in principle anyone can verify what the software does.
This transparency supports trust. Users do not need to rely only on marketing claims or documentation. They can have independent experts audit the code, verify security properties, or confirm that no hidden functions exist.
Transparency is especially important in areas like security, networking, and cryptography. In these domains, the philosophy values "no security through obscurity." Instead of hiding the design, open source projects aim to make the design public and rely on the strength of the implementation and the ability for others to review it.
Community and Merit
Open source projects typically form communities around the software. The philosophy encourages participation based on merit and contribution rather than formal titles. People gain influence by doing useful work such as writing code, updating documentation, reviewing patches, or helping users.
There is often a culture of shared responsibility. If something matters to you, the expectation is that you can help improve it or work with others who can. You are not just a consumer but can become a participant.
This approach is visible throughout the Linux world. Mailing lists, forums, issue trackers, and chat channels allow discussion, problem solving, and guidance for newcomers. The philosophy values learning in public and sharing knowledge freely.
Commercial Use and Business Models
A common misunderstanding is that open source means that software cannot be sold or that it is always non commercial. The philosophy does not forbid selling open source software. In fact, one of the requirements in many open source definitions is that there must be no discrimination against fields of endeavor, including commercial use.
What open source forbids is imposing restrictions that violate user freedoms. You can charge for distributing software or for providing support and services, but you cannot take away the rights granted by the license.
A simple way to state this is:
Let $P$ be the price to access a copy of software $S$. The open source philosophy does not require $P = 0$. It requires that, once a user has a copy, their rights to use, study, modify, and share $S$ are preserved according to the license.
Many companies that work with Linux build business models around support, hosting, customization, and integration rather than selling locked copies of software.
Ethical and Practical Motivations
People adopt the open source philosophy for different reasons. Some are mainly motivated by ethics. They see user control over software as an important right, especially when software affects daily life, privacy, or access to information.
Others are more motivated by practical benefits. They find that open collaboration produces more reliable software, avoids repeated reinvention, and allows faster innovation.
There is also an educational angle. Because the source code is open, it becomes a huge learning resource. Anyone who wants to understand how real systems work can read actual production code, experiment with it, and contribute improvements.
In practice, these ethical, practical, and educational motivations combine. The Linux ecosystem reflects this mixture. It is driven by personal beliefs, commercial interests, and the simple fact that shared code and shared effort can produce powerful results.
How This Shapes Linux
The open source philosophy explains several characteristics of Linux that new users will notice.
Linux exists in many distributions, not just one, because the license and philosophy allow different groups to take the same underlying components and assemble them in diverse ways to fit different goals.
Bugs and new features are often discussed publicly, because open source development favors open communication and review.
Documentation, tutorials, and community help are abundant, because the culture encourages sharing knowledge.
For you as a beginner, understanding this philosophy helps explain why there are so many choices, so many tools, and so many ways to do the same thing in Linux. It also means that, as you gain experience, you can move from being only a user to being a contributor if you wish, whether by reporting bugs, writing guides, or eventually modifying code.
The open source philosophy is not just background history for Linux. It is an active, living set of ideas that continues to shape how Linux evolves and how people interact with it today.