Before installing, you must have Qt 5.2 or higher installed. NGM has only been tested with GCC (MinGW on Windows) 4.7.2. Visual Studio is not supported.
Before you can run Qt, you must have QScintilla installed. You may download it here:
http://www.riverbankcomputing.com/software/qscintilla/download
Please note that for some strange reason, QScintilla does not build with a debug version by default, so if you will be debugging in NGM, you must also create a debug version of the library yourself.
Once all required prerequisites are meet, you can open a terminal and type the following commands in order (NOTE: Qt must be in the system's path. On Windows, a console application is provided with Qt that sets the system path accordingly):
cd Source
qmake Natural-GM.pro
make
To complete the installation process, you must copy over contents from the Resource directory to the location of the executable or build folder. This gives you the default icons and themes. If you do not, you will be seeing NGM naked. Don't look! D: