Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Fix the driver behind crashes, sound loss and screen glitches3Clear out junk files and repair common Windows errorsA free software license gives users the freedom to run a program for any purpose, study and change it, share copies, and distribute modified versions. “Free” means liberty, not price: the license may allow commercial use and the sale of copies. Under the Free Software Foundation’s definition, a program must provide all four freedoms to qualify.
What makes a software license “free”?
The Free Software Foundation (FSF) defines free software by what users are permitted to do—not by whether they pay for it. A program’s license must preserve all four user freedoms. Source code must also be available so users can meaningfully study and modify the program and share their changes. A source file being visible on its own does not prove that the license grants these rights.
As an Amazon Associate I earn from qualifying purchases.
What are the four freedoms?
The FSF numbers the freedoms starting at zero:
- Run the program for any purpose (freedom 0). Users may run it for any purpose without asking the developer’s permission.
- Study how it works and change it (freedom 1). Users may examine the program and adapt it to their needs. Access to source code is necessary for this freedom.
- Redistribute copies (freedom 2). Users may share copies with others, whether at no charge or for a fee.
- Distribute modified versions (freedom 3). Users may share their changes with others. Source code is needed to make this freedom meaningful.
All four freedoms matter. A license that lets people view code but bars them from changing or sharing it does not satisfy the full definition. Nor does a license qualify if it requires modified versions to be distributed under terms that take away users’ freedoms. The FSF’s definition of free software explains the freedoms and their conditions.
Does “free” mean free of charge?
No. As the FSF puts it, “Free software” is a matter of liberty, not price. A copy can be free of charge or sold for money; commercial use, development, and distribution are permitted. The important question is whether users retain the four freedoms, not whether the software has a purchase price.
How to assess a particular program’s license
Do not rely only on a “free” or “open source” label, or on the fact that source code is available. Read the actual license terms and check whether the necessary source code is accessible. For a practical assessment, ask:
- Can users run the program for any purpose?
- Can they access its source code, study it, and change it?
- Can they redistribute unmodified copies, including for a fee?
- Can they distribute modified versions under terms that preserve the four freedoms?
- Are commercial use and distribution allowed?
If a license sets conditions, assess what each condition requires and whether users still retain every freedom. A restriction that rules out a purpose of use or blocks sharing modified versions can conflict with the definition.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How does free software relate to open source?
The FSF says “free software” and “open source” cover almost the same range of programs but express different philosophies and values. That is the FSF’s account of the distinction: the terms overlap substantially, but their advocates emphasize different ideas. The license terms—not the label alone—determine what users are allowed to do.
Quick Recap
Best Value
Rank #3
- Used Book in Good Condition
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
