The open-source KDE desktop environment is making the jump across platforms with broad support for Windows and Mac OS X. The core KDE desktop programs, the KOffice suite, and the Amarok music player are actively being ported.
These efforts are largely made possible by the inherent portability of Trolltech’s Qt development toolkit, the underlying framework used by KDE software. Qt is designed for cross-platform portability and even uses native widgets on both Windows and Mac OS X. Trolltech uses a multi-licensing model that makes Qt available under the GPL for open-source software development and requires programmers to buy a commercial license for proprietary development. Previously, only Mac OS X and Linux/X11 versions were available under the GPL, but Trolltech decided to make the Windows version available under the GPL too with the introduction of Qt 4. This finally opened the door for porting open-source KDE applications to the Windows operating system.