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

The future of Unix

A recent poll by Gartner Inc. suggests that 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.

"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.

"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 Computerworld survey suggests that any migration away from Unix won’t happen quickly. In the survey of 211 IT managers, 90% of the 130 respondents who identified themselves as Unix users said their companies were "very or extremely reliant" on Unix. Slightly more than half said that "Unix is an essential platform for us and will remain so indefinitely," and just 12% agreed with the statement "We expect to migrate away from Unix in the future." Cost savings, primarily via server consolidation, was cited as the No. 1 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 continues, "in the recent Cisco Systems Inc. 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 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."

Regardless of the ultimate fate of Unix, the operating system born at Bell Labs 40 years ago has established a legacy that’s 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 Inc.’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 start-ups 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."

Users: Unix has a healthy future

If you’re among those predicting the imminent demise of Unix, you might want to reconsider. Computerworld’s 2009 Unix survey of IT executives and managers, conducted online in March and April, tells a different story: While demand appears to be down from our 2003 survey on Unix use, the operating system is clearly still going strong.

Of the 211 respondents, 130 (62 percent) reported using Unix in their organizations. Of the 130 respondents whose companies use Unix, 69 percent indicated that their organizations are "extremely reliant" or "very reliant" on Unix, with another 21 percent portraying their organizations as "somewhat reliant" on Unix.

Why are IT shops still so reliant on Unix? Applications and reliability/scalability (64 percent and 51 percent, respectively) were the main reasons cited by respondents. Other reasons included cost considerations, hardware vendors, ease of application integration/development, interoperability, uptime and security.

AIX was the most commonly reported flavor of Unix used by the survey base (42 percent), followed by Solaris/Sparc (39 percent), HP-UX (25 percent) and Solaris/x86 (22 percent), "other Unix flavors/versions" (19 percent), Mac OS X Server (12 percent) and OpenSolaris (10 percent). Of the 19 percent who selected other Unix flavors, most said they used some kind of Linux.

Almost half of the respondents (47 percent) predicted that in five years, Unix will still be "an essential operating system with continued widespread deployment." Just 5 percent envisioned it fading away. Of those who said they were planning on migrating away from Unix, cost was the No. 1 reason, followed by server consolidation and a skills shortage.

Which of the following best describes your Unix strategy?

  • Unix is an essential platform for us and will remain so indefinitely: 42 percent
  • Unix’s role in our enterprise will shrink, but it won’t disappear: 18% percent
  • We are increasing our use of Unix: 15 percent
  • We expect to migrate away from Unix in the future: 12 percent
  • None of the above: 8 percent
  • We have already implemented a plan to migrate away from Unix: 5 percent
  • Other: 2

Which of the following best describes your vision of where Unix will be in five years?

  • It will be an essential operating system with continued widespread deployment: 47 percent
  • It will be important in some vertical market sectors, but it will not be considered an essential operating environment for most companies: 35 percent
  • It will generally be seen as a legacy system warranting a non-Unix migration path: 11 percent
  • Unix, as well as other operating systems, will fade in importance as we go to hosted (cloud, software-as-service, etc.) systems: 5 percent
  • None of the above: 2 percent
  • Other: 1 percent