Linux itself depends on other programs to run, for example, GNU and UNIX. Without these dependencies, Linux would not be able to run programs or even work correctly. GNU (guh-NOO) was a project starred by software programmer Richard Stallman in 1983. It was a completely “free” operating system, but that doesn’t mean that it costs 0 dollars, that means that you get complete freedom to distribute, change, or sell GNU once you obtain it. This was a big deal for Linux, as Linus Torvalds needed something that he could give to people without requiring them to pay for it, and GNU was the obvious choice. Obviously, creating an operating system takes a very extensive amount of time, and by 1990, the founder of the GNU project had completed everything to make a working operating system, except one component, the kernel. This is where the Linux kernel comes in, and the GNU project and Linux collaborated together to make the ultimate operating system of its time, allowing Linux to freely distribute copies of their operating system and the ability to use the GNU library, which was originally designed to be used on UNIX systems. As for UNIX, it's a different story. UNIX was an operating system developed in AT&T’s Bell Laboratories in the early 70s. UNIX became very popular for its ease of use and stable code. By the late 70s, many computer manufacturers were trying to make their own UNIX based computers, and in the early 1980s, UNIX was among the most popular operating systems being used on computers.UNIX was most commonly used in colleges and educational settings, which is why Linus Torvalds had found out about it, at his college. UNIX was solely proprietary, meaning that no one had access to the code, and they could not redistribute it if they bought it. This is ultimately one of the reasons that UNIX went down and is not seen anymore today, only in the form of UNIX-like systems. Because of UNIX being so popular, it was compatible with almost all programs, which is why Linux was built off the UNIX kernel, allowing projects like the GNU project to work with it, and allowing UNIX programs to run on Linux, allowing for the same compatibility you would find in a UNIX system. This was a big deal for Linus, as he wanted to use this himself, and needed the compatibility to be able to use it in college. This is a main motivation for picking to base Linux off of UNIX, and not just base it off itself. This changed the course that Linux would go down and truly changed the operating system race all together.Without UNIX and GNU, Linux would not have been developed, due to compatibility issues and kernel issues. Today, Linux still needs these dependencies, and would not be working without them. UNIX is not in development as of 30 years ago, and the GNU project is actively worked on today by Richard Stallman and many other programmers around the world contributing to the project.