Canonical has introduced the Ubuntu tablet interface, which will compete with Android, iOS and Windows with its own take on multitasking. The launch is the next step in Canonical's quest to unify phones, tablets, PCs and TVs.

Following Canonical's launch of Ubuntu for phones in January, the company is now adding a new tablet user interface tailored for devices with screen sizes from 6 inches to 20 inches and resolutions from 100 to 450 ppi (pixels per inch), the company sai. The resolution leaves room to grow compared to today's tablets. For example, the Nexus 10's 10-inch screen packs in 300 pixels per inch.

Users can start testing the interface on Feb. 21, when the Touch Developer Preview of Ubuntu will be published with installation instructions for the Nexus 7 and Nexus 10 tablets, as well as smartphones such as the Nexus 4 and Galaxy Nexus. Like any cautious company, it notes that the Touch Developer Preview is a developer build and not a consumer-ready release.

The first tablets are expected to arrive at the end of the year, according to an FAQ published by Canonical. You can see more of the interace in the video below.

In general, Ubuntu "is easy to enable on most chipset designs" that are currently running Android, Canonical said. It may sound weird that Canonical is launching a user interface. But that's because the tablet interface is presented by exactly the same OS and code that powers its existing phone, PC and TV interfaces, enabling true convergence, according to the company.

For example, a phone can present tablet, TV and PC interfaces when docked to the appropriate screen, keyboard or remote. Also, the tablet can be used as a thin client with access to remote Windows applications over protocols from Microsoft, Citrix Systems and VMware, it said. All form factors will be merged into a single platform for the 14.04 LTS release of Ubuntu.

To appease large enterprise companies, tablets with Ubuntu will also come with integrated encryption features and the ability for several users to use one device in a secure way.

"We expect to see Ubuntu tablets being adopted initially in enterprise settings where the ability to manage multiple users on a single tablet -- so the tablet can be passed around the office or factory floor, or passed around in medical, military or financial settings -- is very valuable," Canonical founder Mark Shuttleworth said during a conference call on the new offering.

The user interface takes advantage of the screen's edges to navigate between apps, settings and controls. The apps are located on the left edge, and swiping from left to right takes the user to the apps page. That makes for less clutter and room for more content, according to Canonical. There is also the side-stage multitasking feature, which allows a phone application to be displayed on the screen at the same time as a tablet app. So users can take calls in Skype while they work in a document, make notes on the side while surfing the Web, or tweet while they are watching a movie, the company said.

The Canonical team will be available to install Ubuntu on phones and tablets at Mobile World Congress, which starts on Feb. 25.

If Canonical wants to turn its OS and interfaces for phones and tablets into a success it needs backing from developers. The Preview SDK, which currently supports phone app development, will now be updated to also work with tablet apps. On Ubuntu, developers can create a single application that works on phones, tablets, PCs and TVs because it is the same underlying system and all services work across all form factors.

"Developers will be able to ship a single application binary that itself can respond to the different form factors," Shuttleworth said.