Two and a half years after the KDE 4 series of releases began, many users are still using KDE 3. A preference for the familiar seems to motivate some; while others seem influenced by the rumors that began with the botched 4.0 release. Still others want a feature that the KDE 4 series has yet to implement -- or, sometimes, a feature they have been unable to find because of reorganization.
This raises the question: How do the two series of KDE releases compare? The answer is not nearly as simple as you might assume.
The Basic Desktops
For those accustomed to the KDE 3 series, the first impression created by KDE 4 is a great leap forward in visual sophistication. Part of the reason for this impression is that the KDE 4 series supports SVG images for icons and window decorations. However, equally importantly, throughout the development of the KDE 4 series, the developers have paid close attention to visual appearances, with theme and icon developers working in teams, such as the one for Oxygen.The KDE 4 Desktop
You can praise this attention to the visual as being sophisticated, or dismiss it as eye candy, but the fact remains that it makes a difference. Out of the box, KDE 4 releases compare visually with any operating system you can name. By contrast, although you can customize KDE 3 almost out of recognition, as aLinux does, it is still a desktop that reveals its origins in 2002. For better or worse, our concept of what a desktop should look like has shifted, and KDE 3 has not been seriously revamped for some times. Visually, it simply can't keep up.An aLinux Desktop
The same is true on the back end. One of the design changes in KDE 4 is a shift toward engines, or centralized sub-systems for different purposes: for instance, Plasma for desktops, Phonon for multi-media, and Akonadi for personal information management. In addition, KDE 4 has added features that were barely thought of in KDE 3's day, such as geolocation, the semantic desktop, and the social desktop.
When these features work, they expand our thinking about the desktop. However, they require more overhead for the databases needed to run them. Moreover, when they break, they can break catastrophically, as many users -- including me -- have recently found when upgrading Akonadi, which in many distributions has been breaking such essential applications as Kmail, KAddressbook, and most of Kontact. Suddenly, users have had to troubleshoot features they know little about, exploring with almost no documentation how the Akonadi subsystem connects to D-Bus and MySQL.The Akonadi Desktop
Apparently, the more complex a system is, the more that can go wrong. And when it does, the appeal of KDE 3's relative simplicity becomes vastly clearer. If nothing else, KDE 3 is less likely to require hours of troubleshooting.
Still another differences between the two release series is that KDE 4 rethinks the desktop in several fundamental ways.
To start with, KDE 4 uses what might be called a configuration mode, that opens when you unlock the desktop widgets, instead of KDE 3's dialog window of options. While you are in configuration mode, you may not be able to continue other work. At best, icons will have mini-taskbars on their side that get in your way.
Even more importantly, KDE 4 changes what is on the desktop. Unlike with KDE 3, widgets can be placed on the desktop and not just on the panel. Moreover, instead of a fixed selection of icons on the desktop, KDE 4 introduces Folder View -- collections of icons that can be rapidly switched to suit the current task. As an alternative, users can opt for multiple Activities, a sort of enhanced virtual workspace.
In addition, KDE 4 offers any number of miscellaneous new features, such as hot spots on the edges of the desktop to manage and rearrange windows, and the ability to group individual applications in tabs in the same window.
Such changes not only dazzle the mind the way that the improved visuals dazzle the eye, but also make the desktop a more complex place. Although most of KDE 4's innovations are not difficult to learn (assuming all is well), the question may be how many users actually take advantage of them. If a desktop is primarily a place from which to find and start applications, then KDE 3 may very well meet the average user's needs just as well as its successor, and with less distraction.
For such users, KDE 3 might also have the advantage of not distracting users with new concepts and features that are convenient (to say nothing of ingenious) but not essential. In the basics, particularly customization, there is little reason to prefer KDE 4 over its predecessor.
Feature vs Feature
In fact, when you start look at essentials, you cannot always assume that KDE 4 is easier to use. Often, it is not, as in the panel, where it offers a choice of three different menus, control over which notifications display, and the addition of speech notification and holiday calendars on the clock.
Yet, almost as often, KDE 3 displays features that KDE 4 lacks. For instance, where KDE 4 leaves customization of the panel to the desktop theme you select, KDE 3's panel controls allow you to select an image to use for the background, or to set the panel's degree of transparency independently of the them. Similarly, KDE 3 has a selection of pre-defined panel types, most of which you can mimic using the KDE 4 series, but only with effort and ingenuity.
And, unlike KDE3's panel, the one in KDE 4 does not allow you to add applications from the menu. Instead, the closest you can come is to add an applications to the Favorites menu.
In the system settings, the differences are even subtler. KDE 4's System Settings dialog has the advantage of offering both an icon and tree view and its main tab (but not the Advanced one) is more highly organized than KDE 3's Control Center. This higher degree of organization makes finding settings much easier in the KDE 4 series. By contrast, KDE 3's tree view can be formidably long.The KDE 4 System Settings dialog
However, you could argue just as well that the KDE 3 Control Center has the advantage of making settings easier to find because they are all in one window. At times, the Control Center even has features that the newer System Settings lack, including specialized settings for Thinkpad and Vaio laptops.
Admittedly, the current KDE release is missing far less of KDE 3's features than the first release in the 4 series. Yet, even now, you can find cases where KDE 3 either has the advantage or else is more convenient to use. Even after five releases of KDE 4, you cannot always assume the latest is the greatest.
Choosing a Release Series
So which series is preferable? For some, the answer will depend on a few features -- maybe even one -- that one series has and the other lacks.
For others, the answer may be a matter of philosophy and taste. For those who are uninterested in features that might -- theoretically -- improve their work habits, KDE 4 offers few reasons to choose it. For others, KDE 3 might seem to offer more stability and less chance of systemic problems, or, perhaps, enough to satisfy their straightforward requirement.
On the other hand, for those who are adventurous, or want to see some of the latest technologies, KDE 4 seems the clear choice. Few desktops, whether proprietary or free, are more innovative than KDE 4, and, if you choose it, you just might find a way to streamline your work or customize your desktop more exactly to your preferences.
Unless a project takes over KDE 3 development, sooner or later it may become unusable with the latest generation of computers. But, until that happens, the fact that both series co-exist emphasizes two of the advantages of free and open source software: Nothing is really lost, and users can work the way that seems best to them.