This past week at the Mozilla headquarters in Mountain View, we talked to user experience design expert Alex Faaborg about the Firefox 3 visual refresh. He shared some insights about the interface design process and talked about some of Mozilla's goals for refining the look and feel of the Firefox user experience.

Ubuntu 9.04, the next version of the Linux desktop due in April, will definitely feature the new unified, transparent desktop notifications. But non-bleeding-edge Ubuntu users can get them now.

One of the changes Ubuntu 9.10 made from 9.04 was the placement of “asynchronous” farther down the right side of the screen.The problem a lot of users have with this is that it leaves a big space between the top of the screen and notifications.

Canonical's on-screen-display notification agent, implementing the freedesktop.org Desktop Notifications Specification with semi-transparent click-through bubbles.Notify OSD presents these notifications as ephemeral overlays, which can be clicked through so they don't block your work. It queues notifications, to prevent them from flooding your screen.

You’ve certainly have bumped into Gmail Notifier for Ubuntu 9.04 Jaunty Jackalope, the awesome little python-install application that brings Growl-like, transparent Gmail notifications to your desktop, Mumbles goes a lot further than that.

Mumbles tries to bring a more Growl-like interface to Linux notifications. Currently it supports applications such as Firefox, Thunderbird, Amarok, and Twitter's API, among others.

A long time Ubuntu user tries Kubuntu Linux 8.04 live CD with KDE 4.0 desktop and shares his experience.

While we regularly discuss Ubuntu, and to a lesser degree Kubuntu, there's also a version of Ubuntu tailor-made for the Xfce desktop environment. As most of you are aware, it's called Xubuntu, and after trying it out for the first time, I have to say that I find that it provides a better and more coherent experience than Ubuntu (let alone Kubuntu).

Gnome Shell is the new core user interface for Gnome 3 which provides switching windows and applications but you've probably already heard of it by now so I'll skip the introduction.