In KDE's Plasma runtime environment, the developers have invested considerable effort in the "social semantic desktop" engine Nepomuk. Vishesh Handa has written a brand new file indexer to replace Strigi – since KDE 4, the Strigi C++ library has offered the option of retrieving various file attributes such as the length of a song or the size of an image. Handa said that the switch became necessary because of Strigi's difficulties with various common document types and its extensive and difficult-to-maintain code base.
Nepomuk's desktop search feature now also offers a management interface for search tags. The new Nepomuk Cleaner removes things such as duplicate metadata and empty tags in the Nepomuk database.
A lot of work has gone into KDE's KWin window manager, although maintainer Martin Gräßlin describes version 4.10 as "a quiet release for our users". Still, 4.10 is the first version in which KWin uses X-C Bindings (XCB) for some operations. There is a switch in store from the generic Xlib X11 library to the new XCB abstraction layer: this is a requirement for the pending switch to version 5 of the Qt toolkit, which, under Linux, requires either the new Wayland display server or XCB. Gräßlin also explains that XCB offers various technological advantages over Xlib in terms of its interaction with the X Window system.
Visible new additions include minimise and maximise animations in the window manager and the option to completely hide the application menu as a fold-out menu in the window frame. This can be enabled in the system preferences by accessing "Application appearance" ➤ "Style", and then setting the "Menubar style" to "Title bar button"; however, the option is initially only planned to be available in the Oxygen standard theme. If you can't find it, "complain to your distribution", Gräßlin says with a wink in another blog post.
A new Print Manager is supposed to improve the administration of printers within KDE. The Dolphin file manager now better supports file access with MTP, which should help to transfer files to and from mobile devices such as current Android smartphones.
KDE Platform: on the road to QML
KDE 4.10 has ported further parts of its user interface from C++ to QML, which largely remains hidden from the user's view unless one looks very closely. For developers, the move towards QML does have practical significance. For example, developers will now create their widgets with QML "containments" instead of deriving them from the QGraphicsWidgets Qt class. The result from the user's perspective is the same, but the KDE developers hope that choosing QML as their general way forward will allow them to achieve much higher levels of integration and simplification in future releases.
KDE 4.10 is the first to offer a dedicated Plasma SDK called Plasmate, although it mainly addresses the Plasma Active tablet interface. In the traditional KDevelop KDE development environment, developers can look forward to a new unit testing component. Previously, KDE developers had to resort to Qt Creator if they wanted to use QML; now, there is a QML plugin for KDevelop, although KDevelop developer Milian Wolf writes that this plugin is still at an early development stage.
His colleague Ralf Habacker says that the biggest amount of work for this KDevelop release was to finally have ported all Qt 3 classes to Qt 4. Apparently, the notoriously understaffed KDevelop team needed all of 2012 to complete the job. Since 2008, various classes have persistently refused to be ported – for example the "QGraphicsView" class. The developers have now ticked off this task: "This will mean that new features will be easier to implement in future versions", says Habacker, "and that the road is clear for a Qt 5 port as well."
The starting point for the installation and use of the KDE Software Compilation 4.10 is the info page on KDE 4.10. Further details on the new features can be found in separate release announcements for Applications, Workspaces and Platform.