The first alpha release of Ubuntu 11.04 has been released. Here the announcement:

Natty Narwhal is doing a first bit of Spy Hopping, also known as
Alpha 1, which will in time become Ubuntu 11.04.

Pre-releases of Natty are *not* encouraged for anyone needing a stable
system or anyone who is not comfortable running into occasional, even
frequent breakage. They are, however, recommended for Ubuntu developers and
those who want to help in testing, reporting, and fixing bugs.

Alpha 1 is the first in a series of milestone CD images that will be
released throughout the Natty development cycle. The Alpha images are
known to be reasonably free of showstopper CD build or installer bugs, while
representing a very recent snapshot of Natty. You can download it here:

http://cdimage.ubuntu.com/releases/natty/alpha-1/ (Ubuntu Desktop, Server)


Additional ISOs and torrents are also available at:

* http://uec-images.ubuntu.com/releases/natty/alpha-1/ (Ubuntu
Server for UEC and EC2)
http://cdimage.ubuntu.com/kubuntu/releases/natty/alpha-1/
(Kubuntu)
http://cdimage.ubuntu.com/xubuntu/releases/natty/alpha-1/
(Xubuntu)
http://cdimage.ubuntu.com/edubuntu/releases/natty/alpha-1/
(Edubuntu DVD)
http://cdimage.ubuntu.com/ubuntustudio/releases/natty/alpha-1/
(Ubuntu Studio)


Alpha 1 includes a number of software updates that are ready for wider
testing. Please refer to http://www.ubuntu.com/testing/natty/alpha1 for
information on changes in Ubuntu.

This is quite an early set of images, so you should expect some bugs. For a
list of known bugs (that you don't need to report if you encounter), please
see:

http://www.ubuntu.com/testing/natty/alpha1

If you're interested in following the changes as we further develop
Natty, have a look at the natty-changes mailing list:

http://lists.ubuntu.com/mailman/listinfo/natty-changes

We also suggest that you subscribe to the ubuntu-devel-announce list
if you're interested in following Ubuntu development. This is a
low-traffic list (a few posts a week) carrying announcements of
approved specifications, policy changes, alpha releases, and other
interesting events.

http://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-announce

Bug reports should go to the Ubuntu bug tracker:

https://help.ubuntu.com/community/ReportingBugs

Enjoy,

--
Kate Stewart, on behalf of the Ubuntu release team