Canonical on Monday introduced the next version of the Ubuntu Linux desktop, targeting consumers' love of mobile PCs with technology for connecting to a wireless carrier's 3G network through a mobile phone.

In addition, Canonical introduced a server edition of Ubuntu 8.10 that includes improvements in virtualization, Java development and system management. The desktop and server editions are scheduled to be available for free download Oct. 30.

In the desktop version, Canonical has the ability to detect and connect to 3G networks via a notebook's 3G modem through dongles, a mobile phone connected to the PC or a Bluetooth link. The feature is aimed at making Ubuntu a better choice as an operating system for netbooks and other ultra-mobile PCs. Netbooks, a fast-growing segment of the notebook market, are defined as sub-$500 notebooks with screens 10 inches or smaller. The devices, which have keyboards too small for serious document creation, are used primarily for e-mail and Web-browsing.

Canonical has also made it easier for users to take Ubuntu with them. An application added to the OS allows people to write Ubuntu to a USB drive, so the OS can be accessed through another system. The idea behind the feature is to give users a faster, easier option that burning the OS to a CD or DVD.

Another new major feature is the ability to set up a guest session, so the OS can be used by others while keeping the data and programs of the original user inaccessible. Finally, Canonical has incorporated the Gnome 2.24 desktop environment in Ubuntu, which adds features such as a new instant messaging client, a built-in time tracker, the latest Ekiga 3.0 video and audio conferencing tool and improved file management.

In the server edition, Canonical has added a virtual machine builder that the company claims enables VMs to be built from the command line in less than five minutes. The latest version offers full support for Apache Tomcat 6.0 and OpenJDK, making the OS a stronger option for developing and deploying Java applications in production environments.

For security of mail servers running on Ubuntu, ClamAV, and SpamAssassin are now available from the main repository for virus filtering and spam detection, respectably. Support for SATA software RAID controllers is provided via DMRaid, and system administrators have been given the capability to set up a Ubuntu server to provide encrypted private directories that are automatically mounted when users login.

The server and desktop editions are the latest of Canonical's regular Ubuntu releases, which come out every six months and are available with up to 18 months of support. The latest releases are not eligible for Canonical" Long Term Support, which is three years for desktops and five years on servers. LTS is currently available for Ubuntu 8.04.