Canonical, the business side to several open source Linux platforms, has announced the arrival of Ubuntu 11.04.

The release, which has the codename Natty Narwhal, brings with it a number of key features, most notably the introduction of the new Unity UI.

Unity adds the new launcher, located down the left hands side which you can hide and reveal as you see fit, as well as the Dash area, which gives you shortcuts to all your favourite apps and files and a new Spotlight-like search feature.

Workspaces have also had a spring clean, making it easier to keep track of all of your open windows. Handy if you're prone to having loads of apps open at one time.

“This release breaks new ground for Ubuntu by offering users a PC experience that is stylish and efficient,” said Jane Silber, CEO of Canonical. “With this release Ubuntu will recruit an entirely new wave of users to free software. Ubuntu 11.04 is a high watermark for what has been achieved with open-source technologies for the everyday computer user.”

The next Ubuntu update, due in October 2011, is version 11.10 and is codenamed Oneiric Ocelot.

You can grab Ubuntu 11.04 now, over at