Linux (operating system)
Linux is a Unix-like, open source operating system, notable for the fact that it is developed and improved upon through a community effort. Linus Torvalds is the original author of the first versions of the kernel, and is currently the maintainer of the stable releases.
Naming
The original name "Linux" came from the author's name, Linus, along with the "x" in Unix, to show that it is Unix-like. Linus originally intended to call the project "Freax", for Free and Freak, with the "x" denoting that it is Unix-like, but after one of his colleagues named the system's FTP directory after him, the name stuck.[1]
GNU/Linux naming controversy
In the late 1980s, The Free Software Foundation, founded by Richard Stallman, made an attempt to create a free operating system, which they called GNU. They began with the necessary tools for the system, such as a compiler, debugger, and a text editor. Their plan was to then create a kernel to place beneath the tools that they had created. Unfortunately, the foundation was very late in producing a stable release, due largely to the kernel's microkernel nature.
It was during this time that Torvalds first introduced his kernel. Before Linux, hackers had no choice but to use non-free kernels, most notably Minix. While the GNU kernel began to look more and more like vaporware every day, the community received Linux with open arms and many began to contribute.
The GNU community, slightly jealous of the popularity of Linux, soon took up arms against the simple name of Linux. Instead, they decided to call it GNU/Linux, in order to attribute credit to those who worked hard at creating the tools that the Linux kernel runs. Torvalds, however, has made no effort to hide his thoughts towards this naming convention, saying that "calling Linux in general just 'GNU/Linux' I think is ridiculous."[2]
Distributions
Linux is typically found as a package of software known as a Linux distribution. A Linux distribution provides an easy method of installing a Linux system. Among the most notable are Ubuntu, RedHat, and SUSE.
Software
Aside from the GNU project's applications, Linux is capable of running many applications of all natures, from games and graphic editors to Integrated Development Environments and web servers. Among the most commonly used applications are The GIMP photo editing tool, which is commonly referred to as a free alternative to Photoshop, Firefox, a very powerful, tabbed web browser, and OpenOffice, which is a free, full-featured alternative to the Microsoft Office suite.