Open Source vs. Free Software

Open Source vs. Free Software: What’s the Difference and Why Does It Matter?

So you’ve downloaded Firefox and replaced Microsoft Office with LibreOffice? You love these apps so much that you will no longer throw money at Microsoft or Apple and have decided to go 100 percent Linux. But you’ve since discovered that free software doesn’t have quite the same meaning here and you may be wondering why we don’t just call all of this stuff open source for the sake clarity. What’s the big deal? Turns out, free software and open source software aren’t the same. Let’s clear this up.

Origins of the Free Software Movement

Starting in the 1970s, Unix was the dominant operating system. In 1983, Richard Stallman announced a project to create a completely non-proprietary Unix-compatible operating system, the GNU Project. Two years later, he founded the Free Software Foundation with the mission of advocating for, and educating people about, free software.

Stallman didn’t coin the phrase “free software,” which largely referred to software in the public domain. But he expanded on what it meant for software to be free.

The Free Software Foundation defines free software as software that users are free to run, copy, distribute, study, change, and improve. The “free” refers to these freedoms, not price. It just happens to be the case that most free software doesn’t cost money, largely because companies seeking to sell software tend to restrict the freedom of users to copy, distribute, or improve what they buy.

The Free Software Foundation lists four freedoms that it considers to be essential:

Freedom 0 — The freedom to run the program as you wish, for any purpose.
Freedom 1 — The freedom to study how the program works and change it so it does your computing as you wish. Access to the source code is a precondition for this.
Freedom 2 — The freedom to redistribute copies so you can help your neighbor.
Freedom 3 — The freedom to distribute copies of your modified versions to others. By doing this you can give the whole community a chance to benefit from your changes. Access to the source code is a precondition for this.
Coining the Phrase “Open Source”

While the free software label is an explicitly ethical one, the open source label is not. The term formed in the 1990s, after Eric Raymond’s The Cathedral and the Bazaar helped inspire Netscape to release the source code for its Netscape Communicator internet suite.

This, in turn, inspired Raymond and others to see how they could bring the Free Software Foundation’s ideals to the business world. They came up with the term “open source,” and in 1998, Raymond and Bruce Perens founded the Open Source Initiative. The Open Source Initiative provides the 10-point Open Source Definition and it offers a certification mark to apps that are compatible.

The open source movement doesn’t ignore free software values, but it’s more concerned with open collaboration. The goal is for companies and developers to make the code for their software freely available. This way users can trust the programs running on their machines and contribute fixes and features back to the project.

Many of the ethics still align, but the open source movement is less confrontational and more willing to compromise in order to spread adoption.


A Key Difference

The free software and open source movements agree on most of the core values, but they have different definitions of freedom.

The Free Software Foundation embraces copyleft to protect the four freedoms listed above. This legally prevents people from redistributing free software with added restrictions. The organization enshrined this principal in the GNU General Public License. Anyone who uses GPL code has to release their own creations as GPL as well.

Many of the core programs that make Linux and other free operating systems work began as part of the GNU Project. Many of the applications are licensed under the GPL.

Free software licenses are also open source, but not all open source licenses require developers to share their code. Some permit developers to use open source code to create closed source applications, such as the MIT License. These non-copyleft licenses are known as permissive licenses.

While a free software advocate may view the utilization of free software to create non-free software as restricting a user’s freedoms, an open source proponent may be more inclined to view a permissive license as truly free — as in people are free to do whatever they want with the code, even if that means making a proprietary app.

Some particularly prominent individuals contend that some free software licenses, such as GPL v3, have so many conditions that they significantly limit a developer’s freedom.