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.
Qt4 User Interface and Visualization (All Platforms)
Requires: Qt4 headers and libraries, OpenGL or MesaGL headers and libraries.
Mac OS X Lion should use Qt 4.8 or higher, at the time of writing (December 2011) this is available as a release candidate from Nokia.
Motif User Interface and Visualization (Linux and Mac OS X)
Requires: Motif and X11 headers and libraries, OpenGL or MesaGL headers and libraries.
X11 OpenGL Visualization (Linux and Mac OS X)
Requires: X11 headers and libraries,OpenGL or MesaGL headers and libraries.
WIN32 OpenGL Visualization (Windows)
OpenInventor Visualization (All Platforms)
Requires: Implementation of OpenInventor, such as Coin3d with SoXt(SoWin) graphics binding on Linux/Mac(Windows).
X11 RayTracer Visualization (Linux and Mac OS X)
Requires: X11 headers and libraries.
On Linux, it is strongly recommend that you use the binary packages as supplied through the package management system of your distribution. 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 Mac and Windows, we strongly recommend installing any required packages through binary dmg/exe installers supplied through the vendor links above. Note that Mac OS X already has OpenGL and X11 installed, and Visual Studio supplies an install of OpenGL on Windows. Installation of packages on Mac through MacPorts, fink or homebrew is not fully tested or supported, apart from the cases listed above, but you may build Geant4 using packages supplied by these package management systems with that caveat.