KDE desktop for Windows and Mac
Famous(and my favorite) desktop engine KDE is now available for Windows and Mac. What does it means that you can now KDE based applications on Windows and Mac as well and you don't need to write platform specific code anymore. From Wired.
KDE isn't just for Linux anymore. With the recent release of KDE 4, the
K Desktop team has set their focus on porting the core libraries that
power KDE applications over to both Windows and OS X. Although still in
the early stages, there are already builds available for both platforms
that will enable you to compile and run popular KDE application like
the Amarok Jukebox or KOffice suite on either Windows or Mac, and KDE's
goal is to have production-ready versions out later this year.
Windows installer can be download from here