The Linux platform is beginning to gain mainstream acceptance on low-cost netbook devices. The growing popularity of netbooks presents a major opportunity for the open source operating system, but it also comes with some challenges. One of the most significant problems is that much of the open source software that is available today for the desktop is not designed to deliver an optimal user experience on small screens.

Linux distributors and application developers are exploring alternate user interface concepts that will work well at low resolutions without compromising productivity. There is also a clear need to boost usability as netbook devices are broadly intended for the regular consumer market. The KDE desktop environment has recently gained a new specialized netbook interface that leverages the strengths of KDE's unique Plasma technology. Ars tested it on Kubuntu to see how it compares to the conventional KDE desktop experience.

About Plasma

Plasma is a versatile framework that provides the underlying infrastructure of the KDE desktop shell. It hosts several core parts of the user interface, including the panels, desktop icons, and launchers. Plasma's rich architecture encourages a clean separation between functionality and presentation. The presentation layer is resolution independent, which gives it an advantage on devices with unusual screen sizes.

The individual desktop widgets that make up a Plasma-based environment are called plasmoids. They communicate with Plasma's data engine backend to retrieve information which is then displayed to the user. Plasmoids are placed in "containment" objects which control how plasmoids are organized on the screen. Users can have multiple Plasma "activities," which each have their own sets of containments and plasmoids. Plasma's modular approach is advantageous because it makes it much easier for developers to build a custom desktop experience without having to completely reinvent the wheel.

The KDE netbook interface consists of custom Plasma containments and a special theme for KDE's KWin window manager. A slim panel at the very top of the screen provides access to the Plasma activity switcher and displays notification area icons. The environment has two activities: the Newspaper activity, which shows informational plasmoids, and the Applications activity, which serves as a launcher.

Newspaper containment

Unlike the desktop version of KDE, the netbook interface doesn't allow plasmoids to be arbitrarily rotated and placed in the desktop space. The Newspaper activity has a special containment that organizes plasmoids into columns and has scrollbars to permit overflow. As the name implies, it is modeled after a newspaper layout. When the newspaper containment is in editable mode, which can be toggled by clicking the Plasma icon in the bottom-left corner of the desktop, users can click an drag plasmoids to rearrange their order in the layout.

The newspaper containment is designed to work with the growing assortment of plasmoids that are used today on regular KDE desktops. For example, there is a calendar, a weather widget, a Twitter interface, a todo list that synchronizes with Remember the Milk, an RSS tool, and a messaging notification display that will show you incoming e-mail and instant messages. I tested many of these in netbook interface's column layout.

The newspaper containment feels a lot like Internet dashboards, such as iGoogle or Netvibes. It makes a wide range of information immediately accessible in a manner that is well-organized and easy to navigate. The current implementation still has some bugs, however, and needs additional refinement before it will be ready for widespread use. Widgets that don't fit neatly into columns can be somewhat problematic. Some widgets are stretched too wide or don't use enough vertical space.

Application launcher

The KDE netbook developers believe that conventional application launcher interfaces, like the one in the Ubuntu Netbook Remix, misuse the desktop and don't provide enough functionality. To improve on the concept and do more than just display a static list of icons, the KDE netbook developers are repurposing krunner, KDE's interactive query-based launcher.

The Applications activity has a "search and launch" containment that behaves a lot like krunner, but is spread out across the whole desktop. When the user types a query into the search box, the contents of the containment will be populated with launchers that match the query. There are many features that the developers plan to add as they flesh out the search containment, such as a strip that will save the user's favorite launchers.

We really like the idea of using a search-based application launcher directly in the user interface. We''ve explored the benefits of that approach in previous articles, particularly in our latest review of GNOME-Do. The manner in which this functionality is integrated into the KDE netbook interface is intriguing and has some noteworthy advantages. It boosts the discoverability of the query system by making it more accessible to regular users rather than hiding it behind a keyboard shortcut.

Window management concepts

The netbook environment uses some of the sophisticated window management features that are facilitated by KWin's compositing capabilities. Instead of displaying a task list, for example, the top panel has a button that users can click to invoke KWin's "Show Windows" feature, a clone of Apple's Expos?. The environment also uses a custom KWin theme that saves screen space by eliminating window titlebars and automatically maximizing all windows. A button with an "X" icon in the top panel can be used to close the active window.

Artur Souza and Marco Martin, the developers behind the project, introduced it to the KDE community in a presentation at the recent Gran Canaria Desktop Summit. In a blog entry, Souza says that the custom interface was well-received by the KDE community and has already attracted some attention from hardware vendors and Linux distributors.

"We want to create a new user experience on these devices. KDE is not about a specific project anymore, it's all about the user experience: starting on the desktop shell and going far away on social interaction, media, etc," wrote Souza. "I really hope that the community and also vendors can see the potential that we have in our hands and start helping us on this journey and to believe that it's possible."

Marco, who also wrote a blog entry about the desktop summit presentation, has published a video that demonstrates the netbook user interface in action. You can see the special containments and other features that are part of the environment.

Conclusion

The KDE netbook project is still in the early prototype stage and will not be ready for the upcoming KDE 4.3 release. Lead Plasma developer Aaron Seigo has listed it in the roadmap for KDE 4.4, which means it could be ready for users in January.

The prototype is an intriguing real-world demonstration of Plasma's versatility and the strength of KDE's architecture. It's also a good example of how creativity and innovation can move Linux beyond traditional desktop paradigms and make it shine in small spaces. For more details, check out Souza's paper about the project and presentation slides.