Copying a program takes a second and costs nothing, yet writing it may have taken years. Copyright law protects the people who create software, and the licence decides what everyone else may do with it. Learn the four kinds of licence in the syllabus and how to justify the right one for a situation.
Copyright is the legal right of the creator of an original work, including a computer program, to control who may copy, distribute and modify it. A software licence is the agreement that states what a user is allowed to do with the software. Free software (Free Software Foundation) and open source software (Open Source Initiative) give users the source code and let them change and share it. Shareware can be tried free for a limited time or with limited features, then must be paid for. Commercial software must be bought, and the source code is kept secret.
Fig. 1: the four kinds of licence compared
Section 01
Why we need copyright law.
Software is easy to copy perfectly and share instantly. Without the law, anyone could take a program and sell it as their own, and the creator would earn nothing.
What it protects: original work such as program code, music, video, images and text. In the UK, under the Copyright, Designs and Patents Act 1988, it applies automatically when the work is created and lasts until 70 years after the author's death. It protects the code as written, not the idea behind it.
Why it is needed: creators can earn money from their work, so companies can recover the large cost of development; it encourages people to create new software; it stops others copying, selling or claiming the work as their own without permission.
Software piracy: copying, installing or distributing software without a valid licence is illegal. It takes income from developers and pirated copies often contain malware.
Protection methods: licence agreements users must accept, product keys and online activation, and digital rights management (DRM).
Examiner trap
Buying software does not mean you own the program. You own a licence to use it under its terms; the copyright stays with the creator.
Section 02
Four kinds of licence.
All four types are still protected by copyright. What changes is how much freedom the copyright holder gives the user.
Licence
Source code
What the user may do
Typical example
Free software (Free Software Foundation)
Provided
The four freedoms: run it for any purpose, study and change it, give away copies, and share changed versions. Licences such as the GNU GPL are copyleft: changed versions must be shared under the same licence.
GNU tools, the Linux kernel
Open source (Open Source Initiative)
Provided
Use, change and redistribute it, under a licence approved by the OSI. Permissive licences such as MIT allow the code to be used inside commercial, closed products.
Firefox, Python
Shareware
Not provided
Try it free for a trial period or with some features disabled; pay to keep using it or unlock the full version. Copies of the trial may often be shared.
Trial versions of utilities and games
Commercial (proprietary)
Not provided
Pay for a licence to use it; copying, changing or reselling it is not allowed. Licences can be single-user, multi-user or a site licence for a whole organisation.
Office suites, professional design software
Free means freedom: "free" in free software is about liberty, not price. Free software may be sold, but the buyer then has all four freedoms.
FSF and OSI: they accept almost the same licences. The FSF argues that user freedom is a moral right; the OSI stresses the practical benefits of open development, such as more people finding and fixing bugs.
Your turn
State two differences between open source software and commercial software.
Open source provides the source code, commercial does not; open source can be modified and redistributed, commercial cannot; open source is usually obtained without a fee, commercial must be paid for.
Stage 1 · Learn
Check what the sim just showed you
Four quick checks. Each correct answer earns XP and records this skill on your profile.
Quick check+10 XP
What does copyright give the creator of a program?
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Which kind of software is tried free for a limited time and must then be paid for?
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What does copyleft mean in a licence such as the GNU GPL?
Quick check+10 XP
Which kinds of software normally do NOT provide the source code?
Section 03
Justify the licence.
A justify question gives a situation. Choose a licence, then link its features to what the developer or user in the situation actually needs. Generic advantages earn little.
Worked example A company's secret method
A company has spent two years developing route-planning software that uses a method no competitor has. It wants to sell the software to delivery firms. Which licence should it use? Justify your choice.
The company needs income to recover two years of development costs, so a free licence does not suit it.
The method is its advantage over competitors, so the source code must stay secret.
A commercial licence lets it charge each customer, keeps the source code hidden, and forbids copying and reselling.
It could sell a site licence to large firms with many drivers.
Answer: Commercial licence: it earns money and protects the source code.
Worked example A volunteer project
A group of students writes an app to help charities track volunteers. They want as many charities as possible to use it and want other programmers to help improve it. Which licence should they choose?
Charities have little money, so the software should have no licence fee.
Other programmers need the source code so they can fix bugs and add features.
A free or open source licence gives the source code and allows changes and sharing.
A copyleft licence such as the GPL would also make sure improved versions stay free for all charities.
Answer: Free software (FSF, e.g. GPL) or open source licence.
Worked example A new developer
A lone developer has written a photo-editing tool. She wants people to discover it, but she also wants to be paid by those who keep using it.
Shareware lets people try the tool free, which spreads it widely.
Users must pay after the trial or to unlock all features, so she is paid by regular users.
She keeps the source code private.
Answer: Shareware.
Examiner trap
"Open source is free so it is better" is not a justification. Say what the person in the scenario needs (income, secrecy, collaboration, low cost) and which feature of the licence meets that need.
Stage 2 · Exam
Exam-style questions
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Finish the four checks above to unlock the exam questions
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A school wants to install a commercial word processor on all 300 of its computers. Which licence is most suitable?
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Which statement about free software, as defined by the Free Software Foundation, is correct?
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Why is copyright legislation needed for software?
Exam style+20 XP
A company wants to use an open source library in its own commercial product without releasing its own source code. Which type of licence on the library allows this?
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