More than just an operating system, Linux has become a movement leading the open-source charge.

When IBM consolidated its midrange server platform in 2008, it was perceived largely as a convergence of the System i and System p, or AIX, operating systems onto a single hardware platform. The fact that Power Systems would also run Linux appeared as a somewhat gratuitous concession to the growing worldwide interest in open-source software, a trend that was a polar opposite to IBM's traditional proprietary architectures. More than three years later, Linux has emerged as the next up-and-coming star, its presence quietly creeping into embedded systems everywhere and onto enterprise servers in the world's largest organizations.

As Linux this year celebrates its 20^th birthday, its refinement and pervasive adoption in a variety of contexts can't be denied. It seems only the desktop is a holdout—at least so far. Microsoft, with its huge cash reserves, continues to invest in and market Windows, and Apple has its own set of OSes derived from UNIX that it deploys in different versions, depending on the hardware platform. Unlike Linux, both Microsoft and Apple deploy different versions of their operating systems on different platforms. Apple has iOS for the low end, and OS X for the high end. Microsoft has Windows CE for the low end and Windows desktop and server for the high ends.

"Linux has never had that," says Linux author Linus Torvalds in an interview appearing in the upcoming issue of Linux Pro Magazine. "I think it's one reason we are doing really well in the embedded space. We never had a cut-down, kind of castrated version for the low end. We always had full features because, as it turns out, all those high-end features eventually end up percolating down."

Torvalds concedes the desktop market has been resistant to Linux. "It just takes a long time to convince people to change what they're using, so they're still stuck on Windows, and some are still stuck on OS X," he says. But, he adds, "We'll get there someday."

Torvalds continues his oversight work on the Linux kernel, now at V3.0, with hundreds of volunteers and paid developers from across the globe. He began work on his "free operating system" in 1991 as a 21-year-old student at the University of Helsinki, Finland, and has been working on it ever since. The project has grown into a mammoth worldwide undertaking with cost estimates by various organizations ranging up to a remarkable $3 billion in today's currency to redevelop the Linux kernel from scratch. It now has about six million lines of code. Currently, it is licensed under V2 of the GNU General Public License (GPL).

The open-source nature of the Linux project has led to numerous controversies and lawsuits that undoubtedly have impeded, but failed to stop, its growth. One of the more famous suits was that filed in 2003 by the SCO Group against IBM, the latter having contributed code to the Linux project. SCO claimed the contribution was UNIX code for which SCO owned the copyright. SCO then used that claim to warn companies deploying Linux that if they used Linux without a SCO license they could be in violation of copyright law. In response, IBM promised to legally defend its Linux customers should the need arise. The controversy eventually spread into additional lawsuits by SCO against Novell, DaimlerChrysler, and AutoZone, and countersuits by Red Hat and others against SCO, who eventually did not prevail and in 2010 lost to Novell in a celebrated jury trial.

The effect of such legal wrangling, as well as other disputes, both within the Linux community and without, left a chill on the market for some time. Despite this, companies such as Red Hat, Novell (Attachmate), Oracle, and Canonical have pursued enhanced distributions of the Linux kernel and earned revenues from its sales, support, and training. Meanwhile, several of the larger industry vendors, including IBM, Hewlett-Packard, Oracle (Sun), and others have actively supported the development of Linux with donations of hardware, code, and community coordination.

In 1999, IBM founded the Linux Technology Center (LTC) to create an infrastructure for collaboration with the Linux and open-source communities. The role of the LTC was to reinforce Linux' potential as a cost-effective alternative for key business applications in large as well as small and medium businesses. IBM today has some 600 developers participating in more than 100 open-source projects, and the company works closely with Linux distributors such as Red Hat, Novell, Canonical, and others.

"We work closely with Linux distributors throughout the development cycle," says IBM's Jim Wasko, director of the Linux Technology Center, in an LTC position paper. "We develop, test, and support software that has helped the community transform Linux from a useful information technology into a vital, everyday business system."

He notes that the LTC has made significant contributions to Linux that ultimately enabled it to scale beyond 64-processor cores, paving the way for it to be the operating system running some of the world's fastest supercomputers.  The LTC also was a factor in Linux achieving its first common criteria security certification in 2003 and the present-day highest certification level as of 2007. It has developed Linux ports to Power architecture, the mainframe, and Cell Broadband Engine, which enable support on all IBM systems. More than 500 IBM software products run natively on Linux, including DB2, WebSphere products, and system management utilities.

"IBM has the right idea, and Linux so far is pervasive everywhere but the desktop," says Barry Kline, an MC Press Online author who frequently writes about the Linux operating system and its distributions. "It definitely is catching on in many circles," he says. However, Kline is not optimistic about Linux replacing desktop Windows any time soon.

IBM, however, has a vision for the desktop that involves its free suite of IBM Lotus Symphony productivity solutions running on Linux. With its word processing, spreadsheet, and presentations package, Symphony doesn't have quite as many modules as OpenOffice.org, but at least it is uniquely IBM—and it's free! (Symphony also runs on Windows yet is not compatible with the IBM Lotus SmartSuite, Lotus' earlier paid desktop productivity suite that includes the Approach database). IBM Business Partners in areas of the world where Microsoft Windows and MS Office are perceived as quite expensive (such as eastern Europe) have done well with the Linux/Symphony desktop—usually packaged with Ubuntu Linux—that has saved companies thousands. IBM recently donated the code for Symphony to the Apache Open Office project but will still continue to help develop it with additional support from the community. Another popular open source desktop productivity suite is LibreOffice, supported by the Document Foundation. And compatible with the Linux distro Fedora, a project supported by Red Hat and popular among desktop users, are numerous cool tools for Fedora that make it unnecessary to use Microsoft Office or Adobe Creative Suite for most creative work, except perhaps Flash development.

It probably is the broad adoption of the Internet and e-business that has given Linux its greatest boost. Service providers as well as mainstream businesses have taken note of the reliability and low cost of Linux and the companion open-source Apache Web Server, which today runs 60 percent of the world's Web sites. The success of Linux on Web-server farms encouraged data center administrators to try it in other areas, including security devices, load-balancing servers, and file-and print-sharing. Today, Linux-based systems are considered more reliable than Windows systems and are even replacing UNIX systems in many shops because Linux is seen as equally as reliable as UNIX (some say more reliable) and less expensive.

IBM markets a package of DB2 running on Linux on an x86 commodity or IBM server (preferably IBM System x) as a very reliable and affordable solution for companies involved with any sort of e-business. IBM has a number of support offerings within IBM Global Services (IGS) designed to help customers migrate over to Linux from whatever OS they currently run. IGS offers a Linux Strategy Workshop that is a short-term customized workshop designed to produce a high-level strategy for incorporating Linux into the IT environment.  IGS will do an application portfolio assessment to determine the portability of a customer's applications to Linux.  It also offers Linux services to help customers move existing applications to a variety of IBM and non-IBM platforms running Linux.

While the commercial success of companies supporting the distros of Linux has helped Linux grow and evolve, the care and feeding by Torvalds and his band of volunteer developers improving the Linux kernel certainly have kept it on course for the past 20 years. Unfortunately, as we write this, the Linux kernel.org Web site, housing the main Linux code, and the site of the Linux Foundation, have been taken offline due to security breaches. The hacks have enraged the many volunteer developers who work on the project, according to posts left online. The incident was still under investigation at press time, but it is believed the method that Linux uses to distribute and track code changes protected all Linux source files.

The incident undoubtedly will, in the long run, turn out to be a minor blip on the radar screen for an operating system that has become more than just a product; it's a veritable movement, one that is gaining momentum with every passing year.

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