Software Licensing: Open Source, Free and Proprietary Software

Hello students, welcome to Kwickprep. Is free software the same as software you download without paying? Surprisingly, no. Today we will learn about software licences, the difference between proprietary, free and open source software, and why this matters for you.

First, a key term. A software licence is a legal permission given by the owner of the software. It says how you may use, copy, change or share that software. You usually agree to it when you click I agree during installation. If you break the licence, you violate the owner's copyright.

Proprietary software is owned by a person or company that keeps full control. Its source code, the human-readable program, is kept secret. Usually you pay for a licence, which lets you use it but not own it. You are not allowed to change it or share copies. Examples are Microsoft Windows, Microsoft Office and Adobe Photoshop.

Free software is about freedom, not price. The Free Software Foundation, started by Richard Stallman, lists four freedoms. The first is the freedom to run the program for any purpose. The second is the freedom to study how it works and change its source code. The third is the freedom to share copies with others. The fourth is the freedom to share your improved version, so everyone benefits.

Open source software is very close to free software. Its source code is open, so anyone can read it. Anyone may use it, change it and share it, following its licence. It is often built by large communities of developers around the world. Most open source software is also free of cost, so the two ideas are often written together as FOSS, free and open source software.

Students often mix up these words, so let us compare them. Proprietary software usually costs money, and its code is closed. Freeware costs nothing, but its code is still closed, so it is not free software. Shareware lets you try it free for a while, then asks you to pay. Free and open source software is usually free of cost, and its code is open.

Now, some famous licences. The GPL, or GNU General Public License, is the best known free software licence. It lets you use, study, change and share the software. But if you share a changed version, you must share it under the GPL too, with its source code. This rule is called copyleft, because it keeps the software free forever, and the Linux kernel uses it.

The Apache License is a permissive licence, which means it has very few conditions. You may use Apache code even inside a closed, paid product. You must keep the original copyright and licence notice. It also gives users a patent grant, so contributors cannot later sue users over patents in their code. Android and many big software projects use it.

Creative Commons licences are made for creative work like photos, music, videos and notes, not mainly for code. BY means attribution, so you must give credit to the creator. SA means share alike, so your new work must use the same licence. NC means non commercial, so you cannot use it to make money. ND means no derivatives, so you cannot change it. CC zero puts the work in the public domain, with no conditions at all.

Let us apply this to real choices. A photo under CC BY can go in your school video and even on a T-shirt you sell, if you give credit. A photo under CC BY NC can go in your school video with credit, but not on a T-shirt you sell. A photo under CC BY ND may be used only unchanged, so no cropping or editing. Pause and predict: can you edit a CC BY ND photo for your poster? No, ND means no changes.

Why should a student care about licences? Using cracked software is illegal, and it often carries malware. Your school projects must follow licences and credit any code or images you reuse. Free and open source tools give you legal, powerful software at no cost. And contributing to open source projects on sites like GitHub builds a portfolio that colleges and employers value.

Here are open source tools you can use today. Ubuntu Linux is a complete operating system that can replace Windows. LibreOffice gives you a word processor, spreadsheet and presentation program, like Microsoft Office. Firefox is an open source web browser, an alternative to Chrome. GIMP edits images, much like Photoshop. And Python, the language many of you study, is open source too, and is often used in place of paid tools like MATLAB.

There are many more examples. VLC media player plays almost any audio or video file. Android is built on open source code, although phones also include closed Google apps. MySQL is a popular database, and the Apache web server runs a large number of websites. BOSS Linux is an Indian open source operating system developed by C-DAC.

Let us revise what we learned today. Proprietary software has closed code and is usually paid. Free software gives four freedoms, while freeware is only free of cost. Open source software lets anyone use, change and share its code. The GPL is copyleft, Apache is permissive, and Creative Commons is for creative work. Always use licensed or open source tools, and give credit.