Origins of Operating Systems Which operating system family was originally designed by scientists and engineers for use by scientists and engineers?

Introduction / Context:
UNIX originated at Bell Labs in the late 1960s and early 1970s. It was built by researchers to support multiuser, multitasking workloads common in scientific and engineering environments, and it emphasized portability, simplicity, and powerful tools.

Given Data / Assumptions:

• UNIX ancestry includes influential systems and standards (e.g., POSIX).
• Other listed OS families served different target markets: MS-DOS for PCs, OS/2 for enterprise desktops, XENIX as a Microsoft-licensed UNIX variant.

Concept / Approach:
Identify the OS whose design goals and early adopters were primarily in research, academia, and engineering labs.

Step-by-Step Solution:
UNIX: built for time-sharing, programmability, and portability.It introduced the “tools and pipelines” philosophy, conducive to scientific computing.Therefore, UNIX is the correct choice.

Verification / Alternative check:
Historical documents and textbooks trace UNIX’s academic and research proliferation, later inspiring BSD, System V, and modern UNIX-like systems (Linux, macOS).

Why Other Options Are Wrong:
MS-DOS targeted single-user PCs with minimal multitasking.OS/2 focused on protected-mode desktop computing.XENIX was a derivative distribution, not the original research OS.

Common Pitfalls:

• Confusing UNIX with Linux; Linux came later as a UNIX-like kernel inspired by UNIX principles.

Final Answer:
UNIX.