Line Up Support
Once you know what's out there, the first question to ask is where the accountability will rest. What can your team handle, and what kind of support and services program will it need? Because when you commit to a distribution, support is as important a consideration as is the software.

"It's more than just buying the license—it's the support-partner relationship," says Amy Niersbach, platform architect for the city of Chicago. "It really makes a success of that type of implementation."

Although Niersbach says that Novell as "excellent support," the city made its decision to go with Red Hat on its 80 servers for other reasons.

"A lot of people are skeptical to buy Red Hat because they're worried about support—I still hear that from time to time," Niersbach admits. But she says CIOs should also consider third-party support as a viable option. "Dell offers support, HP offers support, and that's an attractive offer for companies."

Since Niersbach's enterprise buys a lot of HP servers, it decided to enter a partnership with HP, which she says has "a lot more to bring to the table" owing to its long history in the UNIX business.

For some, picking out a partner or third-party advocate also provides the accountability answer they need—and even brings down total cost of ownership. According to Ashley, this has proven to be the case at the University of Georgia.

"We typically engage a partner that provides guaranteed support for any enterprise-class system or application," he confirms. "Our experience and research has demonstrated that this is instrumental in maximizing system or application availability at the lowest total cost of ownership."

Look at Your Infrastructure
Lyman says that your existing infrastructure is also going to be a major factor in the decision. It doesn't make sense to adopt a distribution that isn't suited to what your enterprise already has in place.

Look at your enterprise architectures, and make sure they're well-supported with whatever distribution you're considering. Most distributions publish lists that detail their supported hardware; Red Hat does, and Novell has separate lists for the server and the desktop.

The distribution you choose should also play well with the vendors on which you already rely. It was vendor interoperability that swayed the decision for Niersbach. "We're a big Oracle shop, and Oracle's certified on Red Hat," she says.

Red Hat's Oracle and vendor interoperability has helped it win over many an enterprise. This was the case for Wotif.com, the popular Australian-based online business and leisure accommodation booking service. Its servers handle nearly 2.5 million user sessions a month.

"From a commercial perspective, Red Hat has strong relationships with leading vendors, such as Oracle and hardware vendors," says Paul Young, Wotif.com's CIO. "Continuing our association with Red Hat is in line with our ongoing strategy of alignment with key vendors that produce high-quality open-source software that adheres to open standards."

On the other hand, if you're running only a few applications on Oracle or you don't have Oracle at all, you might lean toward Novell's SUSE Linux Enterprise—especially if you have Windows interoperability needs, which Lyman believes is an important differentiator for their brand of Linux.

"That opens it up to a Windows shop, and obviously they might lean toward SUSE Linux," he says.

Last fall, Novell announced the beginning of a collaboration with Microsoft; Novell's senior manager for public relations, Kevan Barney, says this collaboration is now beginning to bear fruit, pointing to recent advances in virtualization, Web services for managing physical and virtual servers, directory and identity interoperability, and document format compatibility.

Other enterprises might even let the vendors do the decision-making for them. That's the experience of Neil Truby, director of Ardenta Limited, a U.K.-based consultancy that helps enterprises deploy Linux. He says that customers often don't know the differences between distros, and will eagerly defer to their trusted resellers and application vendors for a lead.

"For example, customers wishing to run an IBM Informix database will pay, as part of their license, a substantial proportion of that license for vendor maintenance," says Truby. "In this case, the vendor will support the database only on SUSE or Red Hat, so even if we might think that an alternative—say, Ubuntu—might have its merits, our advice to the customer is that it would be madness to invalidate the maintenance conditions from IBM."