Linux is enjoying growth, with a contingent of devotees too large to be called a cult following at this point. Solaris, meanwhile, has thrived as a longstanding, primary Unix platform geared to enterprises. But with Linux the object of all the buzz in the industry, can Sun's rival Solaris Unix OS hang on, or is it destined to be displaced by Linux altogether?

The case for Solaris's demise

Sun officials believe the 16-year-old Solaris platform remains a pivotal, innovative platform. But at the Linux Foundation, there is a no-conciliatory stance; the attitude there is to tell Solaris and Sun to move out of the way. "The future is Linux and Microsoft Windows," says foundation Executive Director Jim Zemlin. "It is not Unix or Solaris."

Solaris, he said, has almost no new deployments and is a legacy operating environment offered by a company with financial difficulties. Original equipment manufacturers also do not see a bright future for Solaris, he claims.

By contrast, Linux is the overwhelming choice for new deployments on x86 systems, Zemlin says. Sun has had its strength in applications such as ERP systems with a seven- to 20-year life cycle, he adds. "What's starting to happen is those life cycles are starting to be completed," and those customers are moving to Linux.

That move to Linux is accelerated by Linux's strength in Web applications, where developers today are focused, Zemlin adds. "You can't really talk to any Web-based application company these days that's not using Linux," he says.

Linux also is less costly to run, Zemlin claims. Sun, he declared, should just move over to Linux. Zemlin also held out little hope for other IBM's AIX and Hewlett-Packard's HP-UX Unix platforms. "It's certainly true that Unix is on the decline," he says.

"Customers are pretty aware that Unix is a more expensive legacy architecture. They continue to support it because they don't want to change their legacy apps over to a new platform because of the costs," Zemlin said. "But they know now they eventually need to do it because Unix just doesn't have the combined might of all the different organizations and individuals that are developing [for] Linux."

Thanks to its strong support of the x86 hardware architecture, "in terms of overall volume, Linux is just a much higher volume product than Solaris ever was," says Al Gillen, an IDC analyst. IDC data show that worldwide Linux shipments in 2006 were about 2.4 million in 2006 and nearly 2.7 million in 2007. By contrast, Solaris shipments totaled 376,000 in 2006 and 371,000 last year.