Linux was written by Linus Torvalds , and has been improved by countless numbers of people around the world. It is a clone, written entirely from scratch, of the Unix operating system. Neither USL, nor the University of California, Berkeley, was involved in writing Linux. One of the more interesting facts about is that development simulataneously occurs around the world. People from Austrialia to Finland contributed to Linux, and hopefully will continue to contribute.
Linux began with a project to explore the 386 chip. One of Linus's earlier projects was a program that would switch between printing AAAA and BBBB. This later evolved to Linux.
Linux has been copyrighted under the terms of the GNU General Public License (GPL). This is a license written by the Free Software Foundation (FSF) that is designed to prevent people from restricting the distribution of software. In brief it says that although you can charge as much as you'd like for giving a copy away, you can't prevent the person you sold it to from giving it away for free. It also means that the source code must also be available. This is useful for programmers. The license also says that anyone who modifies the program must also make his version freely redistributable.
Linux supports most of the popular Unix software, including The X Window System . This is a rather large program from MIT allowing computers to create graphical windows, and is used on many different Unix platforms. Linux is mostly System V , mostly BSD compatible and mostly POSIX-1 (a document trying to standardize operating systems) compliant. Linux probably complies with much of POSIX-2, another document from the IEEE to standardize operating systems. It's a mix of all three standards: BSD, System V, and POSIX.
Many of the utilities included with distributions are from the Free Software Foundation and are part of GNU Project . The GNU Project is an effort to write a portable, advanced operating system that will look a lot like Unix. ``Portable'' means that it will run on a variety of machines, not just Intel PCs, Macintoshes, or whatever. Linux is not easily ported (moved to another computer architechure) because it was written only with the 80386 in mind.
Of course, Torvalds isn't the only big name in Linux's development. The following people also deserve to be recognized:
Of course, I must have missed people in the above list. Sincere thanks and apologies go out to anyone not mentioned here--there must be dozens if not hundreds of you!