Compiling Into from sources is needed if you have an older version of Qt, or if you make changes to the source codes. Qt environment must be set up correctly as described. Open a terminal (Linux, Mac) or Into command prompt (Windows) and type the following commands:

Linux

cd into_install_dir/src
qmake -r MODE=release
make
./install.sh release

Mac OS X

cd /Developer/into/src
qmake -r MODE=release
make
./install.sh release

Windows, MinGW

cd into_install_dir\src
qmake -r MODE=release
mingw32-make
install release

Windows, MSVC

cd into_install_dir\src
qmake -r MODE=release
nmake
install release