4. Software licences

Every time you click “I accept” during an installation, you agree to a contract. A technician must know what these contracts allow, because installing software without the right licence can cost a company a lot of money and can put you in trouble. In this page you will learn the main types of software licence and how to choose and respect them.

How to use this page

1. Read sections 1 to 5 (about 35 minutes).
2. Practise with the tab Licence detective of the Computer System Explorer lab.
3. Answer the questions at the end and do Activity 7.

1. Copyright and licences

Software is a creative work and it is protected by copyright, like a book or a song. In Spain and in the European Union, the author owns the exclusive rights to copy, distribute and modify the program by default. Nobody else may do these things without permission.

A software licence is the contract where the owner gives you permission to use the program, under certain conditions. The licence can say:

• who can use the program (a person, a company, only for non-commercial use);
• on how many devices or for how many users;
• for how long (forever, a subscription, a trial);
• whether you can see the source code, modify it, copy it or sell it.

To use a program legally you must accept and follow its licence. The text of the licence is the only reliable source: names such as “free” or “open” can mean different things.

Piracy has real costs

Using a copy of a paid program without a licence is copyright infringement (piracy). It can lead to fines and claims for companies and, in serious cases, to criminal penalties. In addition, cracked programs are a common way to spread malware, and they do not receive official updates. As a future technician you will be responsible for the licences of the computers that you manage.

2. Free software and open source

The idea of free software was defined by the Free Software Foundation (FSF). A program is free software if its users have four basic freedoms:

Freedom	Meaning
Freedom 0	Run the program for any purpose.
Freedom 1	Study how the program works and change it. This needs access to the source code.
Freedom 2	Redistribute copies, to help other people.
Freedom 3	Distribute copies of your modified versions to others.

Free means freedom, not price. Free software can be sold, and a program that costs nothing is not necessarily free software.

The Open Source Initiative (OSI) publishes the Open Source Definition. It has similar goals but another point of view: it stresses the practical benefits of an open development model (quality, security, collaboration). In practice most licences are accepted by both movements, so people often write FOSS (free and open-source software).

3. Types of licence

3.1 Proprietary software

The owner keeps the rights. You buy or receive the right to use the program under an EULA (End-User Licence Agreement). You cannot see the source code, modify it or redistribute it. Examples: Windows, Microsoft Office, Adobe Photoshop.

Proprietary licences come in several models:

Model	How it works
OEM	Comes pre-installed with a new computer and is tied to that computer.
Retail (boxed or download)	Bought separately; usually it can be moved to another computer, but it is used on one device at a time.
Volume	For companies and schools: one agreement for many installations.
Subscription	You pay every month or year to keep using it (Microsoft 365, Adobe Creative Cloud).

The exact rules depend on the product and on the contract. Always read the EULA.

3.2 Freeware, shareware and freemium

• Freeware: free of charge, but the source code is closed and you may not change or sell it. The author may add conditions, for example “personal, non-commercial use only”. Examples: Adobe Acrobat Reader, IrfanView (free for non-commercial use).
• Shareware / trial: you may test it for a limited time or with limited features and then you must pay. Example: WinRAR, which asks for a licence after the trial period.
• Freemium: a free basic version and paid advanced features. Many mobile apps work like this.

None of these is free software in the FSF sense, because you have no access to the source code.

3.3 Open-source licences: copyleft and permissive

They give you the freedoms of free software. They differ in what happens with your changes:

	Copyleft	Permissive
Idea	Freedom must be preserved. If you distribute a modified or derived program, you must do it under the same licence and give the source code.	You can do almost anything, even include the code in a closed-source product.
Main condition	Same licence, source code available	Keep the copyright notice and the licence text
Typical licences	GNU GPL	MIT, BSD, Apache 2.0
Examples	Linux kernel (GPL v2), GIMP, WordPress, Blender	FreeBSD, Apache HTTP Server, Node.js

Other licences sit in the middle. For example, Mozilla Firefox and LibreOffice use the MPL, which asks you to share changes made to the licensed files but allows mixing them with other code.

Creative Commons are for content, not for software

Creative Commons licences are used for texts, images, music and videos. They combine four conditions: BY (attribution: name the author), NC (non-commercial use only), SA (share-alike: your derived works use the same licence) and ND (no derivatives). For example, the course notes that this unit is based on use CC BY-NC-SA 4.0. For software it is better to use a licence designed for code, such as the GPL or the MIT.

4. What can I do with each licence?

Licence type	Use it	Read the source code	Modify it	Share copies	Sell it	Must you share your changes?
Proprietary (EULA)	Yes, under the EULA	No	No	No	No	Not applicable
Freeware	Yes, free of charge	No	No	Only if the author allows it	No	Not applicable
Shareware / trial	Yes, for a limited time or with limited features	No	No	Often yes, unchanged	No	Not applicable
Copyleft open source (GPL)	Yes	Yes	Yes	Yes	Yes	Yes, under the same licence
Permissive open source (MIT, BSD, Apache)	Yes	Yes	Yes	Yes	Yes	No, but keep the notice

Three common mistakes:

1. “Free of charge” is not “free software”. Freeware costs nothing but gives you none of the four freedoms.
2. “Open source” is not “not commercial”. Companies sell support, hosting and certified versions of open-source software, and some use it in paid products.
3. “I downloaded it, so I may use it”. Check the conditions of use: some free programs are free only for students or for non-commercial use.

5. How to find out and respect a licence

Ask these questions before you install a program for a client or a school:

1. Who is the author or owner? Download from the official website or the official repository.
2. Where is the licence text? Look in the installer, in the About or Help menu, in a file named LICENSE or COPYING in the program folder or in its repository. On Debian and Ubuntu, the file /usr/share/doc/<package>/copyright lists the licences of each installed package.
3. What does it allow? Check the kind of use (personal, commercial, education), the number of devices and users, and the duration.
4. Do I need to keep a record? In a company, keep an inventory of licences: which program is installed on which computer, with which licence and until when. Audits are common.
5. Is there a free alternative? For many tasks there is a good open-source option: LibreOffice instead of an office suite, GIMP instead of a photo editor, Linux instead of a paid OS. Compare not only price, but also compatibility, support and training.

Check what you have learned

1. What are the four freedoms of free software?

   Answer

   Freedom 0: run the program for any purpose. Freedom 1: study how it works and change it. Freedom 2: redistribute copies. Freedom 3: distribute your modified versions.

2. Is a program that is free of charge always free software? Give an example.

   Answer

   No. Freeware such as Adobe Acrobat Reader costs nothing, but its source code is closed and you cannot modify or redistribute it, so it is not free software.

3. A developer wants to include an MIT-licensed library in a closed-source commercial product. Is it allowed? What if the library used the GPL?

   Answer

   With the MIT licence it is allowed, as long as the developer keeps the copyright notice and the licence text. With the GPL (copyleft), if the developer distributes the product, the whole derived work would have to be distributed under the GPL with its source code, so it is not compatible with a closed-source product.

4. What does the SA in CC BY-NC-SA mean?

   Answer

   Share-alike: if you adapt the work, you must share your version under the same licence.

5. A school wants to put the same paid design program on 30 computers. It has bought one retail licence. What should the technician do?

   Answer

   Not install it on all of them: a retail licence usually allows one device. The school needs 30 licences or a volume or education licence, or it can choose an alternative with a suitable free licence. The technician should read the EULA and record the licences in an inventory.

Glossary

English	Castellano
copyright	derechos de autor (propiedad intelectual)
licence	licencia
EULA (End-User Licence Agreement)	contrato de licencia de usuario final
proprietary software	software propietario
free software	software libre
open source	código abierto
source code	código fuente
freeware	software gratuito (freeware)
shareware / trial	software de prueba (shareware)
copyleft	copyleft
permissive licence	licencia permisiva
subscription	suscripción
piracy	piratería
attribution	atribución, reconocimiento
licence inventory	inventario de licencias