The OpenSceneGraph use the CMake build system to generate platform specific
build environment.  CMake reads the CMakeLists.txt files that you'll find 
throughout the OpenSceneGraph directories, check for installed dependnecies
and then generate the appropriate build system.

You can grab CMake from http://www.cmake.org, version 2.4.6 or later.

Under unices (i.e. Linux, IRIX, Solaris, Free-BSD, HP-Ux, AIX, OSX) use the cmake or :
 ccmake commandline utils:
 
  cd OpenSceneGraph
  ccmake .
  make
  sudo make install
  
Under Windows use the GUI tool CMakeSetup.

For further details on compiliation, installation and platform specific information
read "Getting Started" at http://www.openscenegraph.org, under 
"Documentation".