Programming Languages for Building Operating Systems

Building an operating system is a complex and low-level task, and the choice of programming languages is critical. 

Here are some of the programming languages commonly used for building operating systems:

1. Assembly Language: Assembly is the lowest-level programming language and is often the primary choice for OS development. It allows for direct control over the hardware and provides a level of detail required for an OS.

2. C: C is widely used in OS development due to its efficiency, low-level system access, and portability. Many parts of popular operating systems, like the Linux kernel, are written in C.

3. C++: While less common than C, C++ is used in some modern operating systems. It offers additional features like object-oriented programming and can be used for certain parts of an OS.

4. Rust: Rust has gained popularity for OS development, particularly for its memory safety features and performance. It provides low-level control without some of the pitfalls of C or C++.

5. Ada: Ada is a language designed for safety-critical and real-time systems. It has been used in some specialized OS projects, especially in the aerospace and defense industries.

6. D: D is a systems programming language that aims to combine the power of low-level languages like C and C++ with the productivity of high-level languages.

7. Haskell: While not commonly used for building complete operating systems, Haskell has been explored in research projects to develop parts of an OS.

8. Swift: Apple's Swift programming language has been used in the development of macOS and iOS, although it is not traditionally used for building general-purpose operating systems.

9. Java: Java is typically not used for developing traditional operating systems but has found a role in embedded and specialized systems.

10. Python: Python is not typically used to build the core of an operating system due to its high-level nature and performance limitations. However, it can be used in certain OS components or for scripting and automation within the system.

11. Go (Golang): Go is a systems programming language developed by Google. While it may not be the first choice for building entire operating systems, it can be suitable for certain OS components or applications.

12. Lisp: Lisp is known for its flexibility and extensibility. Some experimental operating systems have been built using Lisp or Lisp-based languages.

13. Forth: Forth is a stack-based programming language that has been used for embedded systems and microkernel-based operating systems.

14. Objective-C: Objective-C was historically used in macOS and iOS development but has been largely replaced by Swift in recent years.

15. Real-time Programming Languages: For real-time operating systems, specialized programming languages like Ada, Real-Time Java, and others may be used to ensure predictable and deterministic behavior.

When building an operating system, the choice of programming language is influenced by factors such as performance, control over hardware, safety, and the goals of the project. In many cases, operating systems are developed using a combination of languages, with low-level code often written in assembly or C for maximum control and efficiency, and higher-level languages used for specific components or applications that don't require low-level hardware interaction.