Ubuntu 8.04, codenamed Hardy Heron, was officially released today and is now ready for downloading. The latest release of the popular Linux distribution is the second long term support version meaning it will be supported for the next three years on the desktop and five years on servers. Tectonic has been running Ubuntu Hardy since the first beta and so far we have been very impressed by this new release. At first glance Hardy doesn’t look at that different to previous versions of Ubuntu. Which is probably because the bulk of the changes in this release are under the hood and not in plain site.

PulseAudio
The one change most users are talking about is the inclusion of PulseAudio, an open source sound server that offers a great deal more mixing capabilities than previous sound servers included in Ubuntu. The most exciting of these is the ability to assign different levels to different applications. As new audio applications are loaded they can be controlled individually. So voice over IP calls for example can be set louder than the CD player or a radio stream. PulseAudio also allows for multiple streams concurrently. So one application doesn’t have to switch off for another to play audio.

PulseAudio can also switch audio streams from one playback device to another or even output audio streams to multiple playback devices.

GVFS
The other major change in Ubuntu Hardy, again under the hood, is the inclusion of GIO and GVFS, a new I/O abstraction layer and virtual file system mechanism. GVFS replaces the older GnomeVFS library and is based on D-Bus to co-ordinate the various mounting and file operations. While many of the benefits of GVFS are not immediately obvious there a few hints of the new power. Large file transfers, for example, will be queued in one window rather than multiple windows as before.

PolicyKit
One of the better additions to Ubuntu Hardy is the inclusion of PolicyKit, a new approach to managing users and security. As on all Linux systems critical, and potentially damaging, commands are hidden from regular users without root access. It’s a good idea to prevent users breaking their systems by mistake. In the graphical environment accessing root-only functions was typically accessed by running the gksudo command to open a root-privileged dialog box. With PolicyKit this is no longer needed (at least in most cases). Instead users are able to open system tools and when there is a need for root privileges the dialog box will include, for example, an “unlock” button for users to insert their password to gain access.

The real power of PolicyKit is that, unlike, gksudo, which allows access to entire applications, PolicyKit can be used to lock down specific parts of an application. Using the “authorizations” management tools administrators can define which users are able to effect changes to that element, and how persistent their access is. PolicyKit is an excellent addition for administrators.

Screen resolution
Managing screen resolutions in Hardy Heron has also been improved through a new interface. The screen resolution dialog box is particualry helpful if you have multiple monitors attached to your machine. Each display can be configured with its own resolution. Unfortunately, if you have dual monitors, streching the desktop across two displays is still a task that requires a great deal of fiddling and file editing.

There are also a handful of new applications included by default in Hardy and some that have had an overhaul. Among these is the panel clock applet which has been improved to include support for displaying weather information and times for multiple locations in its expanded view. Hardy also includes the Transmission BitTorrent client which replaces the unmaintained GNOME BitTorrent client. For CD-burning Hardy includes the Brasero CD burning program and an enhanced System Monitor utility.