Unix turns 40: The past, present and future of a revolutionary OS

Unix at 40

Unix turns 40

• The early days of Unix
• Hackers' heaven
• Unix offspring
• The Unix Wars
• "Unix" defined
• The future of Unix

More

• Timeline: 40 years of Unix
• On the shoulders of giants:
  3 Unix movers and shakers
• Survey: Unix has a long and healthy future, say users
• Graphic: The Unix family tree

The future of Unix

The continued lack of complete portability across competing versions of Unix, as well as the cost advantage of Linux and Windows on x86 commodity processors, will prompt IT organizations to migrate away from Unix, suggests a recent poll by Gartner Group.

"The results reaffirm continued enthusiasm for Linux as a host server platform, with Windows similarly growing and Unix set for a long, but gradual, decline," says the poll report, published in February 2009.

"Unix has had a long and lively past, and while it's not going away, it will increasingly be under pressure," says Gartner analyst George Weiss. "Linux is the strategic 'Unix' of choice." Although Linux doesn't have the long legacy of development, tuning and stress-testing that Unix has seen, it is approaching and will soon equal Unix in performance, reliability and scalability, he says.

But a recent survey by Computerworld suggests that any migration away from Unix won't happen quickly. In the survey of 130 Unix users among 211 IT managers, 90% said their companies were "very or extremely reliant" on Unix. Slightly more than half said, "Unix is an essential platform for us and will remain so indefinitely," and just 12% said, "We expect to migrate away from Unix in the future." Cost savings, primarily via server consolidation, was cited as the number one reason for migrating away.

Weiss says the migration to commodity x86 processors will accelerate because of the hardware cost advantages. "Horizontal, scalable architectures; clustering; cloud computing; virtualization on x86 -- when you combine all those trends, the operating system of choice is around Linux and Windows," he says.

"For example," Weiss says, "in the recent Cisco announcement for its Unified Computing architecture, you have this networking, storage, compute and memory linkage in a fabric, and you don't need Unix. You can run Linux or Windows on x86. So, Intel is winning the war on behalf of Linux over Unix."

The Open Group, owner of the Single Unix Specification and certifier of Unix systems, concedes little to Linux and calls Unix the system of choice for "the high end of features, scalability and performance for mission-critical applications." Linux, it says, tends to be the standard for smaller, less critical applications.

AT&T's Korn is among those still bullish on Unix. Korn says a strength of Unix over the years, starting in 1973 with the addition of pipes, is that it can easily be broken into pieces and distributed. That will carry Unix forward, he says: "The [pipelining] philosophy works well in cloud computing, where you build small reusable pieces instead of one big monolithic application."

The Unix legacy

Regardless of the ultimate fate of Unix, the operating system born at Bell Labs 40 years ago has established a legacy likely to endure for decades more. It can claim parentage of a long list of popular software, including the Unix offerings of IBM, HP and Sun, Apple's Mac OS X and Linux. It has also influenced systems with few direct roots in Unix, such as Microsoft's Windows NT and the IBM and Microsoft versions of DOS.

Unix enabled a number of startup companies to succeed by giving them a low-cost platform to build on. It was a core building block for the Internet and is at the heart of telecommunications systems today. It spawned a number of important architectural ideas such as pipelining, and the Unix derivative Mach contributed enormously to scientific, distributed and multiprocessor computing.

The ACM may have said it best in its 1983 Turing award citation in honor of Thompson and Ritchie's Unix work: "The genius of the Unix system is its framework, which enables programmers to stand on the work of others."

Next: Timeline: 40 years of Unix

Gary Anthes is a former Computerworld national correspondent.

Read more about operating systems in Computerworld's Operating Systems Knowledge Center.