Qt 4.7.0 or greater is required.

OS X:
qmake -o Makefile dooble.osx.pro
or
qmake -spec macx-g++ -o Makefile dooble.osx.pro 
make

Unix:
qmake -o Makefile dooble.pro
make

Windows:
qmake -o Makefile dooble.win.pro
make
