Some of the industry's most powerful vendors came to the LinuxWorld Conference and Expo in Boston last week with a simple message: Linux is ready for prime time.

"2005 will be a watershed year," Computer Associates International's new President and CEO John Swainson said in a keynote address. "For the first time, you'll be able to build and deploy an enterprise-class application using only open source technology." Before taking over CA in November, Swainson was vice president of worldwide sales for IBM's Software Group.

Daniel Frye, vice president of IBM's Linux Technology Center, says simply, "Linux is enterprise-ready. It is a high-quality, high-performance and secure operating system."

IBM has 600 people in Linux development, and it is a multibillion-dollar business, Frye says. "Two to three years ago Linux was being used to support individual applications, file and print, etc. Now it's being used to support complex databases and a broad variety of applications, even risk analysis on Wall Street."

He estimates that there are 6,000 business apps available for Linux today vs. a few hundred when IBM got into the business six years ago.

Novell CEO Jack Messman said in a keynote that part of Linux's appeal is a common code base that ultimately will extend from the data center to the server to the desktop, simplifying IT. Novell already has 3,600 of its 6,000 desktops running Linux.

For most users, however, Linux isn't an option on the desktop, and limitations remain that preclude its use in some situations. For high-availability applications, for example, there is more work to do, says IBM's Frye.

But the most troubling questions about Linux aren't technical, but legal in nature. While IBM says the ongoing The SCO Group litigation has no effect in the marketplace, and Novell and others offer to indemnify customers (IBM does not), the SCO suit might only be the tip of the iceberg.

Open source expert Bruce Perens, author of 15 books on the subject, said at a LinuxWorld news conference he was recently recruited as an expert witness for what was described as "the defining Linux patent infringement case" (he was later rejected because of conflicts of interest).

That dark cloud aside, the open source movement has a full head of steam, and it certainly looks like Linux has found a home in the enterprise. It will prevail because of its transparency, says MySQL AB CEO Marten Mickos. "With open source, all problems are known, which puts power in the hands of customers."