Mommy, Where Did Unix Come From?
Sometime in the mid 1960s, a bunch of geeks at AT&T's Bell Labs decided it would be fun to create a new
operating system called Multics. (This was no small task, because computers at the time were about the size
of a football field and two stories high.) Multics fizzled in 1969 when Bell cut the cord, but some of the
geeks continued work on what became known as UNIX; and it became wildly popular inside AT&T.
Since AT&T was not allowed to sell computer software at the time,
it gave away UNIX (complete with
source code) to any educational institution. AT&T produced new
versions of UNIX called System III and
System V in the early 1980s, but all the while, geeks at the University
of California at Berkeley and other
places were busy hacking away on their own versions of Unix based on the
AT&T code. Some cross-pollination did occur, but there are still
significant differences between the Berkeley (commonly called
BSD Unix) and AT&T flavors. In the early 1990s, AT&T sold UNIX
to Novell, which was bought by
Digital Equipment Corporation, which sold it to SCO (Santa Cruz
Operation) in 1995. For the next 15 years,
SCO then tried (with little success) to sue just about everyone,
claiming that Linux or some variant
of UNIX, or a product based on them, violated their copyright and/or
licensing terms. SCO now teeters on
the edge of bankruptcy, after a court ruled in 2010 that Novell is the
owner of the UNIX copyrights.
So how does this affect Linux? Much of the legal wrangling was over whether or not snippets of the
original UNIX code found their way into Linux, and if so, was it a legal violation of any sort. Novell
seems to have put this to rest by stating "We don't believe there is Unix in Linux" and pledging
not to sue anyone over UNIX or Linux ownership issues.
Today, there are now lots of Unix variants sold or given away by many different companies and
universities. While these various flavors can make it difficult to write portable software, efforts to
standardize Unix (two of the more notable ones being POSIX and COSE) offer hope for greater
compatibility in the future.
Like any operating system, Unix has some cryptic commands and less-than-intuitive aspects. (Three of the
most important Unix commands have the peculiar names cat, grep, and awk .) Either serious hallucinogens
or a warped sense of humor came into play at some point in the creation of Unix. I don't let this bother me,
though, taking comfort in my favorite platitude: "Unix was written by geeks on drugs." Seriously, though,
Unix is really no more difficult to learn than DOS or Windows--it's just different.
Can Linux Replace Windows?
Until recently, running Unix meant investing in a powerful workstation that cost megabucks. Linux changes all that, because it's a complete version of the Unix operating system (software that controls the basic functions of the personal computer) that runs on ordinary personal computers. The added fact that it's freely available and "open source" makes it all the more attractive.Linux is also being taken very seriously by the computer industry, with new Linux-compatible versions of popular software packages being announced every month. The Apache Web server software running on Linux platforms powers about half of all Web sites today. Even more telling, Microsoft considers Linux a major threat to its Windows empire.
What Is Linux?
In the early 90s, a geek named Linus Torvalds at the University of Helsinki in Finland thought it would be fun to write a Unix kernel from scratch. He called it Linux, and it was cool but pretty much useless without all the utility programs needed to make it a complete operating system. At the same time, Richard Stallman and his pals at the Free Software Foundation were writing a bunch of freeware Unix utilities collectively known as the GNU Project. It was cool but pretty much useless without a kernel to make it a complete operating system. News of Linux spread quickly over the Internet, and many other Unix programmers joined the effort to enhance it. What we now know as Linux is a combination of Torvald's Linux kernel, the GNU Project software, and some other nifty software bit and pieces developed by programmers from all around the world.Today Linux is a complete and reliable implementation of the Unix operating system, with the following notable features:
- 32-bit or 64-bit operation (it uses all the speed and power of your CPU)
- Virtual memory (it can use all of your system's RAM)
- Full support for X Windows (Unix's standard graphical user interface)
- TCP/IP networking support (allowing connection to the Internet)
- GNU software support (including a huge amount of free Unix software from the GNU Project)
Because of that (and because the author is a nice guy), Linux is free. You can obtain the source code, modify, sell or give away the software so long as you provide full source code and don't impose any restrictions on what others do with it.
