The platforms I listed are the platforms where I know that KDE4
successfully builds.
I don't know if anybody already tried to build KDE4 on NetBSD, AIX, QNX,
HP-UX, IRIX, BeOS, DragonFly, Hurd or any of the other platforms CMake
supports. I'm quite sure the bigger problems in getting KDE4 work there
will be to get all the required libraries working on these platforms
(dbus, some multimedia lib like xine, a compatible X, etc.) and to get
the compiler actually compile the C++ code without errors (some compilers
don't accept everything what gcc accepts, some because they are older,
some because they are more picky).
Alex