Commercial software is software that is sold. Usually the software licence prohibits distribution and alteration of the software. Examples of commercial software include Microsoft’s Windows and Office products, Adobe’s Photoshop, and Apple’s Final Cut. Commercial software is usually licensed for a number of users, depending on the type of licence:
- Single user licences, as their name suggests, allow just one user to use the software on one machine at a time.
- Multi-user licences specify the number of users who are allowed to install the software and use it at the same time. Multi-user licences are sometimes used for software designed for families (e.g. 3 or 4 users) or by organisations (which could be tens or hundreds of users).
- Site licences allow all users within an organisation (often, within a physical site) to use the software without restriction on the number of users. For hundreds or thousands of users, site licences are much easier to manage than many separate per-user licences. Site licences are obviously quite expensive.
Freeware – not to be confused with free and open source software – is software which can be distributed for free. However, the author retains their copyright to the software, and you are typically not permitted to change the software or sell it.
Shareware is software that can be downloaded and tried for free, but requires a payment to the author if you like it and decide to continue using it. Shareware traditionally refers to full, unrestricted software, meaning the author is relying on users’ honesty to pay – however, some software may have limited functionality until a fee is paid.
Public Domain or PD software is software to which the author has given up all rights. This means the software can be freely distributed, changed, and sold. Effectively, the software belongs to everybody (the public).
Free and Open Source Software
Free and Open Source Software (FOSS) should not be confused with freeware or public domain software. The ‘free’ in FOSS refers to ‘freedom’ – the freedom to do what you want with the software. Unlike freeware, you are allowed to alter and sell FOSS. The difference between PD and FOSS is that the FOSS licence requires any changes to the software to also be FOSS. This means if you improve a piece of FOSS, you must release your source code so that other users can benefit too. This is the fundamental idea of FOSS – the licence – sometimes called a Copyleft licence – guarantees your freedom to use the software as you wish. Examples of FOSS include Firefox, Linux, Audacity, and GIMP. I have previously covered common FOSS misunderstandings here and here.
Software licences and the copy protection mechanisms companies use in their software are covered in more detail in chapters 2 of the textbook. Tomorrow’s blog post will cover the licences used for media.