I was just wondering who knows what programming languages Windows, Mac OS X and Linux are made up from and what languages are used for each part of the OS (ie: Kernel, plug-in architecture, GUI components, etc).
I assume that there are multiple languages for each and obviously I know the Linux kernel is written in C.
I'm totally guessing here that Mac OS X contains a lot of Objective-C code as it is Apple's language derived from NeXT.
Windows, I have heard contains C, C++ and Intel Assembly. Do Linux or Mac OS contain any Assembly code?
Also, are there scripting languages like Ruby, Python, etc used by the OS developers for scripting parts of the OS? What parts of the OS would be written in each language?
Windows: Mostly C and C++, some C#
See under the heading One Operating System Running On Multiple Platforms where it states:
You're right MacOSX has Objective-C in the core.
Windows C++
Linux C
About the scripting languages, no, they pretty much high level.
Linux: C. Some parts in assembly.
Mac OS X: Cocoa mostly in Objective-C. Kernel written in C, some parts in assembly.
Windows: C, C++, C#. Some parts in assembler.
Unix: C. Some parts in assembly. (Source)
The Linux kernel is mostly written in C (and a bit of assembly language, I'd imagine), but some of the important userspace utilities (programs) are shell scripts written in the Bash scripting language. Beyond that, it's sort of hard to define "Linux" since you basically build a Linux system by picking bits and pieces you want and putting them together, and depending on what an individual Linux user wants, you can get pretty much any language involved. (As Paul said, Python and C++ play important roles)