Why does my Qt 4.5 app open a console window under Windows?

For those who have this issue using CMake under Windows (see Amoo’s comment), here’s a solution here.

In short, you need to add WIN32 to your add_executable() statements:

add_executable(GuiApplication WIN32 src/main.cpp)

For further details, see the CMake documentation on add_executable and WIN32_EXECUTABLE.