Geant4 has several optional components which if enabled require further software to be preinstalled on your system. These components and their requirements are listed below.
GDML Support (All Platforms)
Requires: Xerces-C++ headers and library compiled against the C++11 Standard.
Qt User Interface and Visualization (All Platforms)
Requires: Qt4 or Qt5 headers and libraries, OpenGL or MesaGL headers and libraries.
Either Qt4 or Qt5 can be used provide that the version of Qt is 4.6 or higher on Linux and Windows.
On OS X, you should use Qt 4.8 or better.
Qt should preferably be compiled against C++11, but this is not required as its ABI is binary compatible between C++11 and C++98.
Motif User Interface and Visualization (Linux and OS X)
Requires: Motif and X11 headers and libraries, OpenGL or MesaGL headers and libraries.
X11 OpenGL Visualization (Linux and OS X)
Requires: X11 headers and libraries,OpenGL or MesaGL headers and libraries.
On OS X 10.11 and higher, X11 can be obtained through the XQuartz project.
WIN32 OpenGL Visualization (Windows)
Open Inventor Visualization (All Platforms)
Requires: Coin3D with SoXt(SoWin) graphics binding on Linux/OS X(Windows). Coin3D is a free implementation of Open Inventor.
X11 RayTracer Visualization (Linux and OS X)
Requires: X11 headers and libraries.
On OS X 10.11 and higher, X11 can be obtained through the XQuartz project.
Freetype Font Rendering Support (Linux and OS X)
Requires: Freetype headers and libraries.
USolids Support (Experimental)
Requires: USolids headers and libraries, compiled against the C++11 Standard.
On Linux, it is strongly recommend that you use the binary packages as supplied through the package management system of your distribution unless these do not meet the version and (for C++ packages) ABI requirements listed. If you require a component that uses OpenGL, we also recommend that you install the OpenGL package supplied for your video card (e.g. NVIDIA). You should consult the documentation of your distribution for information on the packages that provide the needed software libraries and headers.
On OS X and Windows, we strongly recommend installing any required packages through binary dmg/exe installers supplied through the vendor links above. Note that Visual Studio supplies an install of OpenGL on Windows. OS X supplies OpenGL, but if you need X11 you will need to install the XQuartz app. Installation and use of packages on OS X through homebrew and MacPorts is not tested or supported, but you may build Geant4 using packages supplied by these package management systems with that caveat.