Software Licensing
1. The Two Primary Models
A software license is a legal instrument governing the use or redistribution of software. At AS-Level, we focus on the contrast between Free/Open Source and Proprietary models.
Proprietary (Closed Source)
The software is owned by an individual or company. Users buy a license to use it, but do not own the code.
- Source Code: Not available to the user.
- Restrictions: Cannot be copied, modified, or redistributed.
- Support: Usually comes with professional support and regular updates.
Free & Open Source (FOSS)
Software where the source code is made available to the public. Users are encouraged to study and change it.
- Source Code: Fully accessible and editable.
- Redistribution: Can be shared freely (often under the same license).
- Support: Community-driven; no formal guarantees.
2. Commercial Software Variations
| Type | Description | Access to Source Code? |
|---|---|---|
| Commercial | Software produced for sale (e.g., Microsoft Office). | No |
| Shareware | Trial-based software; free for a period then requires payment. | No |
| Freeware | Distributed for free, but copyright remains with the owner. | No |
| Public Domain | No copyright exists. Anyone can do anything with it. | Yes |
3. Intellectual Property (IP) Law
Copyright: Automatically protects original work (like code). It is illegal to copy software without the owner's permission.
Software Plagiarism: Taking someone else's code and claiming it as your own. In professional coding, this is a major ethical breach.
4. The Four Software Freedoms (FOSS)
To be truly "Free Software," a program must provide these freedoms:
- Freedom 0: The freedom to run the program for any purpose.
- Freedom 1: The freedom to study how the program works and change it.
- Freedom 2: The freedom to redistribute copies.
- Freedom 3: The freedom to distribute copies of your modified versions.
Professional bodies like the BCS (British Computer Society) or ACM have Codes of Conduct. These require members to act in the public interest, maintain competence, and respect the intellectual property of others.