Which of the following is not a computer language?

I. C++
II. Java
III. Linux

The correct option is Only III.

To understand why this is the correct answer, let's analyze each of the given options:
I. C++: This is a widely used, high-level programming language developed by Bjarne Stroustrup in 1979 as an extension of the C programming language. It supports object-oriented, generic, and functional programming features.
II. Java: This is a high-level, class-based, object-oriented programming language designed to have as few implementation dependencies as possible, allowing developers to "write once, run anywhere" (WORA).
III. Linux: This is not a computer language. Instead, Linux is an open-source Unix-like operating system kernel, first released by Linus Torvalds in 1991. It serves as the software that directly manages a system's hardware and resources, allowing applications (written in languages like C++ and Java) to run.

Therefore, because C++ and Java are computer languages, and Linux is an operating system, only III is not a computer language.