In free software history, the acronym GNU stands for which recursive phrase?

Introduction / Context:
GNU is a foundational project in the free software movement, started by Richard Stallman in 1983. Understanding the meaning of its name helps contextualize its philosophy and importance in the history of Linux and open-source software.

Given Data / Assumptions:

• The acronym in question is GNU.
• We are discussing the GNU project in computing, not unrelated terms.

Concept / Approach:

GNU is a recursive acronym for 'GNU's Not Unix.' It emphasizes that while GNU was designed to be Unix-compatible, it was developed independently and released as free software. The recursive naming style reflects hacker humor and traditions in computing culture.

Step-by-Step Solution:

Verification / Alternative check:

Check GNU.org project pages, which confirm the recursive acronym. Verify that GNU utilities (gcc, bash, glibc, coreutils) are part of most Linux distros.

Why Other Options Are Wrong:

• Greek Needed Unix, General Unix, General Noble Unix: fabricated expansions with no relation to computing history.
• None: incorrect because the correct phrase is listed.

Common Pitfalls:

• Thinking GNU is just another Unix—GNU specifically emphasizes being independent and free.
• Overlooking that Linux distributions often combine GNU software with the Linux kernel.

Final Answer:

GNU's not Unix.