Prehistoric GNU

I explained about how software libre is about freedom and not price and how the term free software can be confusing. To avoid this confusion some people use the term open source instead of software libre.

I think it’s safe to say that the term open source is more popular (in public) than the term software libre but they’re not the same.

Open source also gives people some freedoms but open source misses the point of software libre. Most open source licenses are also approved by FSF as software libre licenses but in general, you should be careful when a software is considered open source because it can be proprietary.


A software libre respects your freedom to use, modify, and distribute the software. Software libre makes sure you have the four essential freedoms.

  • The freedom to run the program as you wish, for any purpose (freedom 0).
  • The freedom to study how the program works, and change it so it does your computing as you wish (freedom 1). Access to the source code is a precondition for this.
  • The freedom to redistribute copies so you can help others (freedom 2).
  • The freedom to distribute copies of your modified versions to others (freedom 3). 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.

Software libre talks about freedom and users’ rights. A software is considered libre when it respects and provides these freedoms. However, open source means something close, but not identical to software libre.

The open source definition focuses on 10 so-called criteria:

  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.
  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.

What Are the Differences?

The terms “free software” and “open source” stand for almost the same range of programs. However, they say deeply different things about those programs, based on different values. The free software movement campaigns for freedom for the users of computing; it is a movement for freedom and justice. By contrast, the open source idea values mainly practical advantage and does not campaign for principles. This is why we do not agree with open source, and do not use that term.

Richard Stallman

Millions of people around the world are using software libre. For example, a lot of schools/students in India and Spain are using GNU+Linux operating system.

Copyleft Art

However, most of the people never heard about the principals and ethical reasons that have built free software/culture movement. Needless to say that when we’re talking about free software, we mean free as in freedom.

Open source is close to software libre definition but it’s not identical so we focus on the term software libre because it promotes freedom and users’ essential rights.

The free software movement has campaigned for computer users’ freedom since 1983. Not all of the users and developers of free software agreed with the goals of the free software movement.

In 1998, a part of the free software community splintered off and began campaigning in the name of “open source.” The term was originally proposed to avoid a possible misunderstanding of the term “free software,” but it soon became associated with philosophical views quite different from those of the free software movement.

Some of the supporters of open source considered the term a “marketing campaign for free software,” which would appeal to business executives by highlighting the software’s practical benefits, while not raising issues of right and wrong that they might not like to hear. Other supporters flatly rejected the free software movement’s ethical and social values. Whichever their views, when campaigning for open source, they neither cited nor advocated those values. The term “open source” quickly became associated with ideas and arguments based only on practical values, such as making or having powerful, reliable software.

Most of the supporters of open source have come to it since then, and they make the same association. Most discussion of “open source” pays no attention to right and wrong, only to popularity and success; here’s a typical example. A minority of supporters of open source do nowadays say freedom is part of the issue, but they are not very visible among the many that don’t.

The two now describe almost the same category of software, but they stand for views based on fundamentally different values. For the free software movement, free software is an ethical imperative, essential respect for the users’ freedom. By contrast, the philosophy of open source considers issues in terms of how to make software “better”—in a practical sense only. It says that nonfree software is an inferior solution to the practical problem at hand.

For the free software movement, however, nonfree software is a social problem, and the solution is to stop using it and move to free software.

“Free software.” “Open source.” If it’s the same software (or nearly so), does it matter which name you use? Yes, because different words convey different ideas. While a free program by any other name would give you the same freedom today, establishing freedom in a lasting way depends above all on teaching people to value freedom. If you want to help do this, it is essential to speak of “free software.”



The best example for a software libre license is GNU General Public License version 3+. It’s a copyleft license published by the Free Software Foundation and it’s also approved by OSI as an open source license.

But there’s also another licenses. For example, Artistic License version 1 (published by the Perl Foundation) is not a software libre license but it’s approved by OSI as an open source license.

Netscape Public License (published by Netscape) is a software libre license but it’s not an open source license.

A great example is the Do What The Fuck You Want To Public License (WTFPL) which is a software libre license compatible with GPL but is not an open source license.

Netscape’s early versions of Mozilla were released under the Netscape Public License version 1.0. This license is approved by the FSF, but it is not approved by the OSI. So these early versions of Mozilla are Free Software, but not Open Source Software.

Active Agenda is licensed under the Reciprocal Public License. This license is approved by the OSI (currently in version 1.5), but it is not approved by the FSF (it’s listed as unfree, linking to version 1.3). So Active Agenda is Open Source Software, but not Free Software.

Practical Differences

First, some open source licenses are too restrictive, so they do not qualify as free licenses. For example, “Open Watcom” is nonfree because its license does not allow making a modified version and using it privately. Fortunately, few programs use such licenses.

Second, when a program’s source code carries a weak license, one without copyleft, its executables can carry additional nonfree conditions. Microsoft does this with Visual Studio, for example.

Finally, and most important in practice, many products containing computers check signatures on their executable programs to block users from installing different executables; only one privileged company can make executables that can run in the device or can access its full capabilities. We call these devices “tyrants”, and the practice is called “tivoization” after the product (Tivo) where we first saw it. Even if the executable is made from free source code, and nominally carries a free license, the users cannot run modified versions of it, so the executable is de-facto nonfree.


As the advocates of open source draw new users into our community, we free software activists must shoulder the task of bringing the issue of freedom to their attention. We have to say, “It’s free software and it gives you freedom!”—more and louder than ever. Every time you say “free software” rather than “open source,” you help our cause.