KDE 4 is the latest release of the K Desktop Environment, which was started in 1996 and has had major releases in 1998, 2000, and 2002. One of the original goals of the project was to create an environment which, in addition to being intuitive and easy to use, provided integrated, consistent applications. It's also Free Software: distributed under the GNU General Public License, anyone can use, copy, distribute, and make derivatives of KDE. KDE 4 is the latest release and it has many new features and advantages. KDE 4 has been restructured from the ground up; it is not just a new skin over the same product. KDE uses a software library called Qt 4 which makes writing programs for KDE much simpler, so that programmers can focus on writing feature-rich, high-quality programs for the users. In fact, many of the key new technologies in KDE 4 are designed to make writing programs simpler, so that the end user gets a higher-quality product In the past, many programs lacked useful features, because implementing them would take too much work and expertise. For example, see the recent rise of dual- and even quad-core processors. They're becoming more and more common, but in order for programs to take advantage of them, they need to be specially written for it, and it can be quite difficult. So in KDE 4 a new tool called ThreadWeaver was made to make it easier. There's also Phonon, which makes it simple to have applications with integrated sound and video, and Solid, which makes accessing hardware easy and crossplatform. Another new thing in KDE 4 is support for Windows and Mac OS X in addition to Linux operating systems. KDE4 applications look and feel native to each platform, so it will use the visual style of that platform. Oxygen, the visual theme, is also new for KDE 4. It aims to have a consistent and intuitive look across all platforms, and be beautiful at the same time.