Ubuntu Linux is coming to smartphones. Canonical – the British outfit that oversees Ubuntu – has built a new version of the open source operating system for touchscreens, and unlike other smartphone operating systems, it will work as a full desktop OS when connected to a monitor, keyboard, and mouse.

"We are confident that Ubuntu will ship on phones from large manufacturers in 2013," says Canonical founder Mark Shuttleworth.

Shuttleworth sees the new version of the OS appealing to two markets: entry-level smartphone consumers and enterprises that want to give employees just one device instead of two or three.

While Apple and Microsoft have developed separate operating systems for desktops and phones, Canonical is pushing a single operating system that can adapt to different devices. For example, touchscreen apps developed for the phone OS will also work on the desktop version of Ubuntu.

"We think these things can converge both on the front end and under the hood," Shuttleworth says. "One of the core visions is complete convergence of the platform from phone to supercomputer."

Ubuntu already runs desktops, servers, and even TVs, and Shuttleworth says a version for tablets is "coming soon."

Canonical is entering an already crowded market for smartphone operating systems. It will compete with other cross-device operating systems such as Android, Windows Phone, and Mozilla's forthcoming Firefox OS, and with other smartphone brands like the iPhone and BlackBerry. "We're sanguine about the challenges that we face, but we know this is an industry that turns itself over every couple years," Shuttleworth says.

Although Canonical claims Ubuntu is running on over 20 million desktops, it's still tiny compared to Windows. And developer interest has waned in recent years thanks in part to Apple OSX, smartphones and web applications. But Linux has been slowly making gains in the desktop market, despite skepticism about the Unity interface released in 2010.

Following controversy over the Ubuntu's Unity interface – and Canonical's decision to include Amazon affiliate links in its search application – the company has moved key Ubuntu development out of the public eye, potentially alienating some of the very people Canonical needs to build applications for the platform. But Shuttleworth is confident that developers are still interested.

"We are the only Linux distribution that has a full pipeline for developing applications and publishing them to an app store," he says, and he points out that Ubuntu is still the most popular distribution of Linux for the desktop. He also thinks that once people see the touchscreen version of Ubuntu they will understand the decisions made around Unity.

He also notes that thanks to Ubuntu for Android – which was released last year – users will be able to try the interface on their Android phones without committing to it. But Ubuntu won't run Android applications, because although Android is based on Linux it has its own application environment.

The other big question is whether manufacturers and carriers want to support and carry another smartphone brand.

"All of our conversations with manufacturers and network operators indicate that they are hungry for another partner," Shuttleworth says. Ubuntu is compatible with the Android Board Support Package (BSP), which means it should be able to run on practically any device that can run Android, which will make it easier for manufacturers to adopt. And Canonical will provide engineering services to help manufacturers deal with supporting multiple operating systems.

As for carriers, Shuttleworth says Canonical is releasing a framework that will enable them to integrate their own services into the operating system.

But what about fragmentation? Shuttleworth says that in some ways it's more controlled than Android because Canonical will be directly managing and updating the operating system, not vendors. He says that Ubuntu is more open overall than Android, but it will be more closed in terms of keeping the experience consistent. "Branding doesn't need to lead to fragmentation," he says. He admits that someone could fork the project, as Amazon did with Android, but doesn't think most vendors want to undertake such a project.