Linux and the Unix Philosophy
1.3 Linux: A cast of one plus one million
If it can be said that Ken Thompson is the inventor of Unix, then Linus Torvalds, at the time a Finnish student at the University of Helsinki, invented Linux. His now famous newsgroup posting on August 25, 1991, that began with "Hello everybody out there.… I'm doing a (free) operating system" sealed his fate forever.
The similarities between Thompson and Torvalds are curious, to say the least. One could argue that Thompson wrote the program Space Travel just for the fun of it. Torvalds, in his fascination with Minix, another Unix-like operating system, found it all too interesting to make a version of a popular Unix command interpreter, bash, run on his "toy" operating system. Again, what started out as "for fun" ended up changing fundamental aspects of the software industry.
Linux didn't start out as a portable operating system either. Torvalds had no intentions of porting it beyond the Intel 386 architecture. In one sense, his back was against the wall, because he had only a minimal amount of computer hardware available to him. So he made the most of what he had without intending to take it any further in the beginning. He found, though, that good design principles and a solid development model eventually led him to make Linux more portable for purity's sake alone. Others carried the ball from that point and ported it to other architectures soon afterward.
By the time Torvalds's Linux came along, the idea of borrowing software written by other individuals had become fairly commonplace. So much so, in fact, that Richard M. Stallman formalized it in his landmark GNU Public License. The GPL is a legal agreement applied to software that virtually guarantees that the source code to the software remains freely available to anyone who wants it. Torvalds eventually adopted the GPL scheme for Linux and, by doing so, made it possible for anyone to borrow the Linux source code without fear of legal entanglements associated with copyright infringement.[1] Since Torvalds was giving away Linux for free, it was only natural that others would contribute their software gratis to the Linux development efforts.
From its early days, Linux had already exhibited that it was indeed a Unix-like operating system. Its developers embraced the tenets of the Unix philosophy wholeheartedly, then went on to write a new operating system from scratch. The catch is, almost nothing in the Linux world is written from scratch anymore. Nearly everything is built on top of code and concepts written by others. So Linux became the natural next step in the evolution of Unix or, perhaps more accurately, the next big leap for Unix.
Like Unix, Linux has its share of developers who helped it along in the early stages of its technical development. But whereas the number of Unix developers at its peak numbered in the thousands, the number of Linux developers today is in the millions. Talk about extreme Unix! It is this massive scale of development that virtually guarantees that Unix's descendant Linux will be a system to contend with for a long time to come.
A new wrinkle that Linux brought to the Unix world is the idea that so-called "open source" software is better than "proprietary" software or software for which the source code isn't readily available. Unix developers have believed that for years, but the rest of the people in the computer industry were being fed lots of propaganda by proprietary software companies that anything borrowed or free cannot be as good as something for which one has to pay money—sometimes huge amounts of money.
The Linux community is more savvy about marketing too, having learned that companies can successfully sell inferior software to millions if it is marketed well. This is not to say that Linux is inferior software, only that, unlike its Unix community predecessor, the Linux community recognizes that even the best software in the world will not be used unless people know about it and realize its true worth.
We will be covering these topics in more depth later. For now, let us leave the history of Unix and Linux in the past and move on. Things are about to get much more interesting.
[1]Torvalds borrowed much more than the GPL. Stallman and others have pointed out that Linux is really the operating system kernel. Much of everything outside the kernel comes from the Free Software Foundation's GNU Project. The purists rightfully call the complete system "GNU/Linux," of which the Linux kernel is an essential component. Having given credit where credit is due, we recognize that most of the world has already recognized "Linux" as the nomenclature of choice.