Gallery: The 20 most significant events in Linux's 20-year history

1991: This message, sent back on August 25th 1991 to the Minix Usenet newsgroup, is usually seen at Linux's true birth. Little did Torvalds know just how wrong he'd be when he wrote, of his  new free operating system  that it would “just a hobby, won't be big and professional like gnu for 386(486) AT clones.”

1992: Andrew Tannenbaum, operating system guru and creator of Minix, an educational operating system version of Unix, declares “LINUX is obsolete” and Linux's first operating system war is on. In the resulting discussion, Torvalds makes a very telling comment about his vision for Linux which remains true today, “If the GNU kernel [another attempt to create a free Unix-like operating system] had been ready last spring, I'd not have bothered to even start my project: the fact is that it wasn't and still isn't. Linux wins heavily on points of being available now."

1993: There were earlier Linux distributions, such as MCC and Yggdrasil Linux but Patrick Volkerding's Slackware was the first broadly successful Linux distro and it's still being updated and used today. 

1993: Debian Linux, the popular community Linux, gets its start. Today, it's the ur-source for MEPIS, Mint, Ubuntu, and many other popular Linux distributions. 

1994: Marc Ewing creates Red Hat Linux. Bob Young buys Ewing's company, merges it with his own, and forms Red Hat, the most successful Linux company to date. 

1995: Linux has its first trade conference, Linux Expo. Many more will follow Today, there are over a dozen major regional and national Linux trade shows in the U.S. alone.

1996: KDE, one of Linux's most significant desktop interfaces is started. In the same year, after working with Slackware and then Red Hat Linux...

...SUSE releases its first standalone Linux .  

1997: The GNOME desktop starts. It, along with KDE, will become one of Linux's two most important desktops. 

1998: Microsoft starts to target Linux. Eric S. Raymond, an early Linux and open-source leader, reveals the so-called Halloween Documents, which reveals that Microsoft takes Linux seriously as an enemy and starts to formulate its anti-open-source and Linux campaigns.

1999: Corel releases the first mainstream Linux desktop. While unsuccessful, it would set the path for other Linux desktop distributions, such as Ubuntu, to try to win the hearts and minds of non-technical desktop users. 

1999: Linux is first benchmarked against, and beats, NT in file serving. The Linux vs. Windows server operating system wars are on. 

2000: In 2000, IBM announced that it would invest a billion dollars in Linux in 2001. This may have been IBM's best investment ever.  While commercially a huge success, it's marketing was decideily counter-culuture as you can see from IBM's Peace, Love, and Linux image.

2001: After some delays, Linux 2.4 is released. With Linux 2.4's vastly improved support  for clustering, multiple processors and  large memory space, Linux becomes competitive with Solaris and other high-end server operating systems. 

2003: SCO, formed from the old SCO Unix company and the Caldera Linux business, turns its back on its Linux history and sues IBM and other companies and tries to prove that Linux is a copy of Unix. The company fails, but for years its FUD bedevils Linux's commercial acceptance. 

2004: Ubuntu  is created. Built on top of Debian Linux, Ubuntu is probably used on more Linux desktops than any other desktop distribution. 

2005: Any doubt about Linux being a major business player is smashed by Linus Torvalds appearance on the cover of BusinessWeek. The tagline? Linux Inc. 

2007: The Open Handset Alliance, which includes Google and numerous hardware vendors, announces Android, arguably the most popular 

2008: The New York Stock Exchange, soon to be followed by many of the other major stock exchanges of the world, switches to Linux for its core operating system. Linux isn't becoming big business. Linux is big business.

2011: IBM's Watson computers, running Linux, wins at Jeopardy and sets a new standard for expert systems.