One of the big visual changes just happened in KDE 4, the transition of kdelibs to the Oxygen Icon set. This transition is still in progress, and it includes a massive icon naming scheme change that affects thousands of files. But, the Oxygen artwork project much is more than just an icon set, it's a unified way to do artwork for KDE 4. SVG an essential part of Oxygen, so many applications that are now capable of SVG display are also using Oxygen styled artwork.