Canonical today is unveiling Ubuntu for tablets, a touch-based interface supporting screen sizes of anywhere from 6" to 20", and use cases targeting both businesses and the home.

The announcement is hardly a surprise given Canonical's recent unveiling of Ubuntu for smartphones, with the first handsets expected to ship in October. Canonical hasn't told us when it expects hardware vendors to ship tablets running Ubuntu, but it's possible Ubuntu smartphones and tablets are on the same schedule.

As previously reported, a developer preview of Ubuntu for phones is scheduled to be released on Thursday of this week. That phone preview can be installed on the Galaxy Nexus or Nexus 4. It turns out the developer preview for tablets will also be available the very same day, and it can be installed on Nexus 7 or Nexus 10 tablets. A software development kit that supports phone app development will be updated to support the creation of tablet apps.

"Installable images and source code will be available from developer.ubuntu.com," and Canonical employees will install Ubuntu on your phones and tablets in person if you visit their booth at Mobile World Congress in Barcelona next week, the company said. A Canonical spokesperson told us that the code coming out Thursday is an early build and "not ready" for in-depth reviews and tests.

UPDATE: Canonical now says it expects mobile devices to ship with Ubuntu in Q1 2014. The October timeline reported earlier was just for the software, not actual devices.

Canonical provided us with a press release in advance of today's announcement, and founder Mark Shuttleworth will talk to press on a conference call today. We will follow up with more details after that call—Canonical declined to answer any of our questions in advance.

Like Ubuntu phones, Ubuntu tablets can become full PCs

For now, let's talk a little more about what we know. Ubuntu for tablets will run on ARM chips (at least), supporting screen sizes from 6" to 20" and resolutions from 100 to 450 pixels per inch. Just like Ubuntu for phones, an Ubuntu tablet can be docked with a keyboard, mouse, and monitor to provide a full PC experience.

Although Ubuntu is supposed to run smoothly on entry-level tablet hardware, the docking can only happen with "high-end silicon." Canonical did not specify what types of chips are required for Ubuntu tablets to double as PCs, but with phones the requirement is a quad-core Cortex A9 or Intel Atom processor and at least 1GB RAM. While it stands to reason that Intel chips would be supported on Ubuntu tablets, the announcement we have doesn't mention any specific processor platform besides ARM.

Tablets in PC mode will be able to access Windows applications remotely through standard protocols from Microsoft, Citrix, VMWare, and Wyse.

Canonical is clearly targeting businesses with the aforementioned Windows support as well as full disk encryption, support for multiple user accounts on a single device, and an IT management tool covering Ubuntu servers, PCs, smartphones, and tablets. “An Ubuntu tablet is a secure thin client that can be managed with the same tools as any Ubuntu server or desktop,” Stephane Verdy, head of enterprise desktop and thin client products at Canonical, said in the announcement.

The tablets aren't business-only, though. A one-minute video Canonical showed us yesterday displays a very Kindle Fire-like experience in scrolling through available TV shows and movies. The video also shows that the tablet interface is largely similar to the Ubuntu phone interface but obviously scaled up to the bigger screen size.

Just after this story published, Canonical posted an additional, longer video with Shuttleworth describing the tablet experience:



The tablets will support split-screen multitasking, as we saw a user making a video call on one part of the screen while manipulating a business document on the other side. "Ubuntu allows a phone app on the screen at the same time as a tablet app," Canonical's announcement said. Canonical calls the ability to have two apps on-screen right next to each other "side stage." It looks like it operates similarly to the Windows 8 "snap" feature, which snaps two applications next to each other.

Canonical has been promising that Ubuntu will ultimately provide one operating system for phones, tablets, desktops, servers, and even supercomputers. Some of the design decisions for Ubuntu on the desktop do seem to have been geared toward bringing Ubuntu to touch screens. The application launcher—a customizable list of icons on the left side of the Ubuntu Unity desktop—is being brought to phones and tablets to provide quick access to apps. Further, the Ubuntu Dash tool for searching one's desktop has been expanded to allow search of both local files and the Internet (notably, with Amazon search results baked in). It looks like that same universal search will be front and center on the Ubuntu tablet interface.

Voice control can be used to manipulate the Ubuntu tablet interface's heads-up display.

Here are some more of the features of Ubuntu for tablets, as Canonical describes them in its press release:

Secure multi-user: Multiple accounts on one tablet with full encryption for personal data, combined with the trusted Ubuntu security model that is widely used in banks, governments and sensitive environments, making it ideal for work and family use.

Voice controlled HUD productivity: The Heads-Up Display, unique to Ubuntu, makes it fast and easy to do complex things on touch devices, and transforms touch interfaces for rich applications, bringing all the power of the PC to your tablet.

Edge magic for cleaner apps: Screen edges are used for navigation between apps, settings and controls. That makes for less clutter, more content, and sleeker hardware. No physical or soft buttons are required. It’s pure touch elegance.

Content focus: Media is neatly presented on the customizable home screen, which can search hundreds of sources. Perfect for carriers and content owners that want to highlight their own content, while still providing access to a global catalogue.

Full convergence: The tablet interface is presented by exactly the same OS and code that provides the phone, PC and TV interfaces, enabling true device convergence. Ubuntu is uniquely designed to scale smoothly across all form factors.

Who will sell Ubuntu tablets? That's to be determined

One of the big questions for both Ubuntu phones and tablets is who will build them. Being able to install preview software on Nexus devices will be nice, but Canonical won't reach a major audience unless smartphone and tablet manufacturers get on board.

Canonical said that hardware manufacturers won't have to start from scratch, because Ubuntu for phones and tablets will run on pretty much anything that already runs Android. "For silicon vendors, Ubuntu is compatible with any Linux-oriented Board Support Package (BSP)," Canonical said. "This means Ubuntu is easy to enable on most chipset designs that are currently running Android."