🐧 GNU
What is GNU?
GNU stands for
GNU’s Not Unix (recursive acronym 😄)
It is a free software project started in 1983 to create a Unix-like operating system that is completely free.
Founder
- Started by Richard Stallman
- Backed by the Free Software Foundation (FSF)
Goal of GNU
To give users freedom, not just free-of-cost software.
GNU provides
- GNU Compiler Collection (
gcc) - GNU C Library (
glibc) - GNU Shell (
bash) - Core utilities (
ls,cp,mv, etc.)
📌 Important exam line:
Linux kernel + GNU tools = GNU/Linux operating system
📜 GPL
What is GPL?
GPL stands for
General Public License
It is a free software license written by Richard Stallman for the GNU project.
Purpose of GPL
To ensure that software remains:
- Free to use
- Free to modify
- Free to share
This concept is called copyleft.
🔓 Four freedoms of GPL (VERY IMPORTANT ⭐)
- Freedom to run the program
- Freedom to study the source code
- Freedom to modify the program
- Freedom to redistribute copies (original or modified)
🔁 Copyleft (exam keyword)
- If you modify GPL software
- And distribute it
- You must release your code under GPL
👉 This prevents software from becoming closed-source later.
🆚 GNU vs GPL (Exam Comparison Table)
| GNU | GPL |
|---|---|
| A project / OS initiative | A software license |
| Develops free software | Defines rules for using software |
| Started in 1983 | First released in 1989 |
| Provides tools & utilities | Protects user freedom |
| Example: GNU Bash | Example: GPL v2, GPL v3 |
📝 One-line exam answers
- GNU: A free software project to create a Unix-like OS
- GPL: A free software license that guarantees user freedoms
- Copyleft: Modified GPL code must remain GPL