With more than 8 million users, Ubuntu Linux is among the most popular Linux distributions.

But what is its mission? What are Ubuntu and Canonical, its lead commercial sponsor, really all about?

Ubuntu has desktop and server releases, and is gearing up both user and cloud services, all of which are set to be updated in the new Karmic Koala release due out later this week. With all the different products and directions, Ubuntu founder Mark Shuttleworth faces questions about the focus and definition of the distribution, as well as the profitability of its corporate backer.

In a press conference call today, Shuttleworth tried to explain.

"The mission of Canonical is to deliver all the benefit of free software to a variety of audiences," Shuttleworth said. "We started with desktop, because we thought that was place we could make the most distinctive splash. The desktop was largely neglected and at the same time there were changes afoot in the core infrastructure of Linux at the kernel level that meant we were confident we could surprise people at how easy [it was] to install and use the desktop if someone was focused on it."

Ubuntu competes against multiple Linux distributions, including those from Red Hat and Novell, as well as community-based distributions. Both Red Hat and Novell offer enterprise Linux desktops, though specific efforts focused on the consumer segment are not currently the main thrust.

Shuttleworth said that Ubuntu to date has been successful in expanding the Linux desktop footprint, and is now interested in increasing the number of places where it can deliver the benefits of open source software.

"We've already done a lot of work in developer ecosystem and we're now increasingly interested in the non-developer consumer ecosystem, so that's what all the OEM work is about," Shuttleworth said, declaring that his focus was on "making sure that Ubuntu gets pre-installed and Ubuntu is available from Dell.com and others and making sure that Ubuntu is the default alternative to Windows."

He added that Canonical has a similar vision for Ubuntu on servers and in the cloud. He admitted that having different products for different market segments does represent some real challenges for Canonical as a small firm.

In terms of the company's organizational structure, Shuttleworth said that there is a core Ubuntu platform team at Canonical, which is divided into desktop, server, mobile and netbook groups. On the sales and marketing front, separate groups are tasked with focusing on OEM, enterprise and consumer efforts.

"It is a stretch and it is a challenge," Shuttleworth said. "But the real prize for us is to show that the free software ecosystem can be delivered as a platform which spans from the most lightweight devices right the way through to the most heavy-duty devices."

He added that there are real benefits to having a complete platform, giving developers the opportunity to both develop and deploy applications using Ubuntu's brand of Linux.

"The consistency of platform and ecosystem is highly valuable to us and to our users. That's why we've given ourselves the harder job of delivering a complete platform rather than going for a specific niche market," Shuttleworth said. "Time will tell whether it's achievable. It's wonderful to do the impossible so long as it's not actually impossible. We're certainly surfing close to the edge of that line."

But the broad product mix poses a threat to Canonical's profitability, at least in the short term. It's a concern that Shuttleworth recognizes, but he sees the silver lining in the longer-term picture.

"I have no concerns about our ability to be profitable," Shuttleworth said. "If necessary, we would have the option to focus on specific areas that are already self-sustainable. My preference is to push the organization faster, to continue to invest in and to continue to create the feeling of a complete platform."

Canonical is a privately-held company, and Shuttleworth does not disclose its financial performance. Last year, he admitted that Canonical was not cash-flow positive.

"Profitability is a matter of choice as to how much we're willing to invest, whether we see the appropriate returns on that investment and whether we see it as the right thing to be doing," Shuttleworth said. "Right now I'm absolutely convinced that we want to be delivering Ubuntu as an end-to-end solution, and that requires us to invest in multiple theatres of battle at the same time."